squash-grow-guide

Section 1: The History of Squash

“Squash” is a rather strange-sounding English word. Early American settlers adapted it from the native Narragansett word “askutasquash.” By the time of European contact, multiple varieties of squash had been domesticated and were being cultivated throughout South, Central and North America.

How old is squash?

The historical significance of squash can’t be overstated. It’s the first known cultivated plant in the Americas.

In fact, archaeologists found domesticated squash seeds in the Guilá Naquitz cave in Oaxaca, Mexico that date back 10,000 years. For reference, this is nearly as old as the earliest agricultural societies in Mesopotamia (modern day Turkey), which are considered to be the first agricultural societies in the world.

Rather than having a single point of origin, genetic studies have revealed that wild squash varieties were independently domesticated by various Native American groups at least six different times throughout pre-Columbian history. Upon his return to Europe, it’s believed that Columbus brought back various varieties of squash seeds which were soon spread throughout the world and bred into new varieties.

Three Sisters – The First Cultivated Companion Plant System?

Interestingly, squash was cultivated in the Americas 4,000 years before either beans or corn (maize). Once combined, the three plants made a powerful agricultural arsenal.

Various Native American populations often grew the three crops (squash, bean and corn) together in companion plant systems (aka “plant guilds”) known as the “Three Sisters.”

  • The beans fixed atmospheric nitrogen in the soil, thus fertilizing the corn and the squash. The beans also helped stabilize and provide structural support for the corn.
  • The corn provided a trellis for the beans to climb on, while also providing shade for the low-growing squash plants.
  • The spiny-stemmed squash plants helped keep pests off of the corn and beans while shading out weeds that would otherwise compete for nutrients.

After harvest, the biomass from the three crops was returned to the earth, enhancing soil fertility. Crops from the Three Sisters also complimented each other nutritionally, providing a wholesome combination of carbohydrates, protein, fats, amino acids, and essential vitamins and nutrients.

*It should also be noted that there were often additional “sisters” in various Native American cropping systems. A common fourth sister was sunflowers and/or sunchokes (Jerusalem artichokes).

Ready to learn how to grow squash from seed organically?

Read this squash growing guide to learn how to grow squash using organic methods — including how to save your own seeds!


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Germinating squash seeds; how to start squash from seed and image of squash seedlings

Section 2: Squash seed germination

There are two basic methods you can use to germinate your squash seeds:

Option 1: Germinate indoors in biodegradable pots:

A little more time-consuming (you have to to keep track of watering your seedlings and making sure they are getting enough light), but you may be able to achieve slightly earlier harvests because you can put out more mature plants after your frost date.

However, with squash and other cucurbits, we’ve found that the difference between starting indoors vs. direct seeding outdoors is negligible in terms of how soon you’ll get to harvest. They have a large seed that germinates rapidly so once you factor in “transplant shock,” they should end up producing their harvests at roughly the same time regardless of whether they’re started indoors (before the last frost date) or outdoors (after the last frost date).

Option 2: Germinate outdoors via direct seeding into your soil:

The easier, less time-consuming approach, but you might not get yields until a bit later in the season since you get a later start.

Choose whichever seed germination method is best for you based on the time of year, your level of gardening experience and the resources you have available. 

Based on the approach you decide to take, read the next sections about starting your seeds indoors or outdoors.


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Section 2a:

Option 1: Starting your squash seeds indoors

squash-indoors<

Part 1. WHEN TO START YOUR SEEDS

Find your last frost date here. 3-4 weeks before your last frost date is the ideal time to start your squash seedlings indoors if you want to get an early jump on the growing season.

If: a) your last frost-date has already passed, b) your soil temperatures are at least 70°F, and c) your local 10-day weather forecast does not have any temperatures forecast below 50 degrees, you’re probably better off direct-seeding your squash seeds outdoors.

Part 2. WHAT TO PLANT THEM IN

POTS: Use in biodegradable peat/paper/cow pots. These pots will be placed directly in the ground during transplanting where they’ll biodegrade in your soil while causing virtually no disturbance to the sensitive roots of your squash plants. Place a plastic seed tray or an old cookie sheet underneath your indoor squash seedlings to keep water from dripping onto your floors or furniture.

Sowing depth: Sow your squash seeds 1-2″ deep in your choice of organic seed starting mix or potting soil.

Do NOT fill your seed cells with soil from your garden, since this tends to harden into an impenetrable brick.

Instead, we recommend that you buy a ready-made organic seed starting mix or a light potting mix like Fox Farm potting soil. Experienced gardeners or gardeners starting large numbers of plants often prefer to mix their own seed starting mix. If you want to make you own seed starting mix, here’s our recipe.

Seedling labels – Don’t forget to label your squash seedling pots using plant markers so you can keep track of each variety from seedling to harvest.

Part 3. GERMINATING CONDITIONS

WARMTH: The ideal temperature range for squash seed germination is 70°-95°F.

Place your seed trays in a warm spot in your home (such as a sunny window). OR for best results, use a seed heat mat (which is also very helpful for starting other summer seeds like tomatoes, eggplants, peppers, etc.). We have significantly better germination with our summer seeds when using a heat mat.

Squash germination time: If the soil is kept damp and temps are kept between 70° – 95°F, your squash seedlings will germinate within 6-10 days. If the temperatures are much cooler than this, your seeds may take an additional 1 – 2 weeks to germinate or not germinate at all.

WATER:

To help with germination, make sure your seed containers stay moist, but not wet. The moisture level should feel like a well wrung-out sponge.

Also make sure to use a gentle watering method such as a misting bottle or a watering can with a very soft pour to prevent the seeds and soil from becoming dislodged. It’s important that your soil mix be thoroughly moistened BEFORE your seeds are added, or you’ll have difficulty getting the soil moist without dislodging the seeds.

The frequency you’ll need to water your seedlings on an ongoing basis varies. Start by watering your seed containers every 24 hours unless they stay really damp. If that happens, hold off and check on them again in a few hours.

Note: The soil will dry out faster on seedling heat mats or under hot lights.

Again, go for the happy medium of soil with a similar dampness as a wrung-out sponge. Seeds allowed to sit in puddles quickly rot whereas tiny seedlings in crusty, dry soil will soon die due to lack of moisture.

Part 4. ONCE YOUR SQUASH SEEDS HAVE SPROUTED

INDOOR LIGHT:

As soon as your seeds have germinated/sprouted above the soil surface, place them in front of a sunny, south-facing window in your home (e.g. the window that gets the most sunlight throughout the day).

Newer, modern windows block a lot of the light spectrum that plants need to grow, so if you have energy-efficient windows, you might want to consider getting grow lights. Here’s how to build your own DIY grow light system.

It’s crucial that your squash seedlings get adequate light—an absolute minimum of six hours of direct light daily—otherwise they’ll quickly become weak and “leggy” (tall and spindly).

Tip: If growing in front of a window, periodically turn your seed trays so that the same side is not always facing towards the sunny window—this will prevent the side furthest away from the window/sun from getting leggy or stretching sideways towards the light.

OUTDOOR LIGHT:

When the daytime temperatures begin to get into the 60s, you can start putting your squash seedlings outside in direct sunlight. However, if you don’t “harden off” your seedlings before exposing them to direct, unfiltered sun, you risk them becoming sunburned.

You can read more about how to harden off your seedlings in the Transplanting Outdoors section below.

Part 5. FEEDING YOUR SQUASH SEEDLINGS:

cucurbit-leaves

The first two leaves on your squash seedlings are called “cotyledon” leaves. The next leaves that develop are the first set of “true leaves.”

About 7-10 days after germination, your squash seedlings will get their first true leaves. At this point, you’ll need to consider nutrition, depending on whether your seed starting mix did or did not contain nutrition.

When/if your seedlings need nutrition (yellowing leaves or stunted growth are sure signs), you’ll want to start using an organic liquid fertilizer 1-2 times per week. (We like liquid kelp fertilizer.) Dilution ratios vary from product to product, but watering at half-strength (half of what the
bottle recommends for feeding mature plants) is a good rule of thumb for seedlings.

Be aware that over-fertilizing your plants can make them extra attractive to pest insects like aphids which can proliferate rapidly indoors since no predatory insects are around!

Next, keep a close eye on your squash seedlings to make sure they stay healthy: well-sunned, well-fed and well-watered until your last frost date has arrived. You’re almost ready for transplanting!


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Section 2b.

Option 2: Starting your squash seeds outdoors / direct sowing

squash-outdoors
click to enlarge

Part 1. PLANTING

After your last frost date has passed, directly sow your squash seeds 1-2″ deep in your garden. Make sure the soil is moist, but not wet, until seed germination/sprouting. Dry soil will not provide conditions necessary for germination or healthy sprout growth.

Part 2. PESTS

Other than weather, the greatest danger to your young outdoor squash seedlings is cutworms, which will chew through the stem of your young seedlings. To stop cutworms from eating your young seedlings, we recommend using the “stick trick.”

The Stick Trick: Once a squash seed has sprouted, find a stick roughly the diameter of a toothpick and gently insert it into the ground directly next to your squash seedling’s stem. The cutworms are tricked into thinking the hard stick is the stem and move on.


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squash transplanting

Section 3: Transplanting Squash Outdoors

If you started your squash seeds indoors, see the below instructions for a general hardening off schedule. If you germinated your seeds outside in your garden, you can skip this section and go to the Sun, Soil and Water section.

Part 1. HARDENING THEM OFF:

squash: hardening for transplanting outdoors

Outdoor direct sunlight is always more intense than either indoor grow lights or light filtered through a window.

Many new gardeners make the mistake of immediately transplanting their seedlings outdoors into direct sunlight before “hardening” them off. This mistake can cause extreme sunburn that severely damages or kills your plants.

To be safe, plan to harden off your squash seedlings outdoors over the course of a week as follows:

  • Days 1-3: Place your squash seedlings outdoors in a shady spot that will only get 3-5 hours of direct sunlight throughout the day.
  • Days 4-5: Place your seedlings in a slightly sunnier spot that will get about 5-6 hours of direct sunlight.
  • Days 6-7: Place your seedlings in a full sun spot (6+ hours of direct sunlight).

Water – If your seedlings’ leaves appear limp, this is likely due to lack of water. Try to keep their soil moist, but not wet.

Sunburn – If you notice your seedling leaves beginning to look white and papery, they’ve gotten sunburned. Put them in a part-full shade spot for a few days and allow them to recover. Again, if you don’t properly harden off your seedlings, they can get severely sunburned, which will either slow their growth to a crawl while they recover or possibly kill them (if they’re small or weak).

Cold – Also, be sure that you bring your squash seedlings inside any time the temperatures drop below 50ºF.

Part 2. PLANTING OUTSIDE:

Once the last frost date for your area has arrived and your squash seedlings are all hardened off, it’s time to plant them outdoors.

Before you start planting, make sure to look at your local 10 day weather forecast on www.weather.com. If you see any day or night temperatures below 45°F, hold off on transplanting. This tip has saved us quite a bit of heartache over the past few years as extreme weather and temperature fluctuations have becomes the “new normal.”

Part 3. PLANTING AND MULCHING:

Squash spacing and placement

Pay careful attention to the type of squash you’re planting when considering your squash plant spacing (distance between plants) and row spacing (distance between rows of plants). A vining squash can easily take up an entire 4×10 garden bed whereas a bush squash will only take up a portion of the bed.

Be sure to follow the spacing recommendations for the specific variety/cultivar of squash you’re growing. As a general rule:

  • Bush/summer squash should be spaced about 2′ between plants with rows 6′ apart (if you grow in rows).
  • Vining/winter squash spacing will vary greatly depending on variety-specific vine growth habit/vine length. Spacing between vining squash plants varies from 2′-4′ with row spacing variation from 6′-12′. Keep in mind that small-fruited winter squash (example: acorn squash) can be grown on a trellis to reduce space requirements.

Planting

We know this may seem obvious to some people but you’d be surprised at how frequently new gardeners are unaccustomed to how deep or shallow to place a root ball and what constitutes real “soil” for filling in the surrounding hole…

Take a look at where your seedling decided to place its stem vs. its roots when it came up in your soil block or container. The point where the stem extends above the soil and the roots spread below it is called the “crown” of a plant. Most transplants want to be placed at approximately the same depth that they “planted themselves.” (Exceptions to this rule are plants like tomatoes, which have adventitious roots that can grow from their stems.)

Plant your squash seedlings such that the soil level in your garden is the same as the soil level in the seedling cell — not sticking above the soil level (which will cause moisture to wick out) and not below the soil level (which can cause the tender young stems to rot). Mature vining squash plants (aka winter squash) can set new roots at each new stem joint, but bushing summer squash plants do not form additional roots.

If you don’t have rich, healthy soil where you plan to grow your squash plants, consider getting worm castings and organic fertilizer to amend your soil as follows:

  • Castings/compost – Dig a 1′ x 1′ hole and fill it with 50% castings and 50% garden soil before transplanting.
  • Organic fertilizer – Loosen the soil in a spot about 3-4x larger than the seedling root ball. Mix in slow release fertilizer at the application rate described on the product package, then transplant the seedling into the spot. 

When filling the hole back in around the root ball, the soil used should be actual soil. You should not fill the hole with recognizable chunks of mulch, kitchen scraps, leaves, lawn clippings, or other undecomposed organic matter. 

Mulching

We can’t overemphasize how important top-dressing your beds with wood chips or mulch is for building and maintaining healthy soil, regulating soil moisture and temperature, and blocking unwanted plants – aka “weeds.” After you plant your squash seedlings, make sure to put at least a few inches of mulch on top of the soil surface around your plants, if it’s not already there.

Again, mulches should always remain on the surface of the soil, not against the roots of the plant (aka “top-dressing).

If you have ever heard of mulches or compost “stealing” nutrients from garden plants, mixing these items into the soil instead of letting them sit on top of the soil is what causes this problem. You can read more about your plant’s long term soil requirements in the Sun, Soil, and Water section below.

Part 4. WATERING:

Immediately after transplanting, give each newly planted squash seedlings a deep watering around the base of the plant.


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Planting squash - sun, soil, and water needs

Section 4: Sun, Soil, and Water Needs for Squash

Sun:

Squash plants thrive in full-sun spots (6-8+ hours direct sunlight per day). Vining squash varieties that can stretch to get more light can tolerate part shade but will generally produce less and smaller fruit.

Soil:

Squash plants are heavy feeders that perform best in rich soil with lots of organic matter. It’s hard to provide too much fertility for squash plants.

Five techniques that you can use to drastically improve your soil health & biological fertility are:

  1. “hugelkultur” (click here to read about this technique);
  2. polyculture plant guilds (see “Guild Plants,” the next section in this guide);
  3. top-dressing your soil with 3-6 inches of wood chips/mulch twice per year in the fall and spring;
  4. using living cover crop mixes rather than leaving your soil fallow;
  5. using compost from hot composting methods (Berkeley method) or worm castings. Either: a) Apply the compost/castings on top of your beds, or b) Make actively aerated compost tea (AACT) to use as a soil drench or foliar spray. (Option b gives you the most bang for your buck.) Both methods of application drastically increase the quantity and diversity of beneficial microbes in your soil and on your plants.

All five of these soil building techniques can improve your soil fertility to the point that your plants will not require any additional fertilizer and virtually no additional water throughout the growing season once their root systems get established.

We recommend that you NOT use non-organic/synthetic fertilizers as these will have a compounding harmful effect on your soil over time. Instead, plan to build your soil fertility for the long-term using techniques that build biological soil fertility.

Water:

Squash need approximately 1″ of water per week.

If your soil is healthy, your plants have established their root systems and rain is regular, you may not need to provide any additional water to your mature squash plants. If you do need to water, water deeply (shallow watering can lead to shallower root systems).


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Squash guild plants, squash companion plants

Section 5: Helpful Guild Plants/Companion Plants for Squash

Definition: A plant “guild” is a polyculture plant system (multiple plant species planted together) purposefully designed to create symbiotic relationships between species, increase plant productivity and generate higher survival rates amongst the individual plants in the guild system.

If you’ve ever visited a “wild” ecosystem (mature forest or prairie), you’ve unknowingly seen plant guilds. Like people, plants tend to perform better in communities than they do as isolated individuals.

Some Common Plants to Consider in Your Squash Guild:

Vegetables

  • beans (bush or climbing, although climbing beans may compete for sunlight and are better grown on a trellis behind/north of your squash so as not to block sun)
  • buckwheat (technically this is a grain plant not a veggie, but the leaves can be eaten as a salad green)
  • cabbage
  • carrots
  • corn
  • alliums (plants in the onion family)
  • peas
  • icicle radishes
  • maize/corn (when grown with bush squash, plant maize so as not to block sun; when grown with vining squash, placement less important)

Herbs

  • basil
  • bee balm
  • catnip
  • dill
  • hyssop
  • mint
  • oregano
  • parsley
  • tarragon
  • yarrow

Flowers

  • borage
  • Jerusalem artichokes/sunchokes
  • marigolds (French and Mexican)
  • nasturtiums
  • sunflowers
  • tansy


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Section 6: Planting Squash in Your Edible Landscape or In Containers

All squash varieties (bush or vining) can be especially attractive in an edible landscape due to their large, dramatic leaves, conspicuous golden flowers, and prominent fruit shapes and colors. In addition, squash also boast versatile growth habits that allow them to fill multiple niches in an ornamental design. Whether you choose bush squash varieties for their compact, rounded shape that doesn’t have that “unruly veggie patch” look or larger vining squash that can quickly fill in an area with lush foliage, squash is a high performing aesthetic vegetable.

A yellow zucchini squash plant graces the tip of the center bed in this highly diverse edible organic home landscape.

A yellow zucchini squash plant graces the tip of the center bed in this highly diverse edible organic home landscape.

In edible border plantings, we recommend using bush squash varieties in various spots throughout the landscape to tie together your design with a dramatic, repeated element but also because this helps to confuse pest insects that want to lay eggs on their favorite food. If you have a garden arch or tall, sturdy trellis, vining varieties are perfect for these dramatic hardscaping elements.

When choosing companions for squash in the ornamental edible garden, it’s important they be vigorous enough that they aren’t enveloped by the squash plant’s enormous leaves and that they ideally provide textural contrast by having a different shape of growth and foliage. It’s also a good idea to play with color combinations in addition to leaf shapes. Some good textural options are grassy, strappy-leafed plants such as onions, garlic, lemongrass, or garlic chives.

For color, consider bright annual flowers that attract predatory insects that will control squash pests (daisy-shaped blooms or clusters of tiny, shallow blossoms like alyssum or yarrow work the best), summer-loving plants with colorful foliage such as amaranth, orach, perilla/shiso, purple basil, or Okinawa spinach.

If you’d like to see hummingbirds flitting around your squash, consider one or two seedlings of trumpet-blooming cypress vine (too many cypress vines—Ipomoea quamoclit—will likely overwhelm the squash, but a single vine tends to coexist peacefully due to its lacy foliage allowing light to pass through to the squash). Cypress vine varieties usually have red flowers which contrast vibrantly with the sunset-yellow hue of most squashes, but can also be found in more gentle white or pink.

Planting Squash in a Container

  • Container Spacing for maximum harvest: Minimum container size: 5 to 15 gallons per plant.

The compact growth habit of bush squash varieties make it one of the best options for using in planters, though even the dwarf/bush varieties still require a very high volume container because squash is a heavy feeder that does not like to dry out between waterings. Unless you are using a very large barrel or raised planting box, it is best to give this type of squash it’s own solo pot. This is also true for vining varieties, which will also need a very sturdy trellis (consider securing the pot to a wall or other permanent structure to prevent the container from overturning once it becomes top-heavy).

Alternately, you can plan to wind a vining squash in concentric rings on the ground around its pot to keep it compact (note that if it is not on a paved surface it will send out roots into any soil it comes in contact with). If you do decide to use a large container and add some companion plants with your squash, you may want to consider a tall annual sunflower, perennial sunchoke, or okra trellis with a climbing legume vine like pole beans or perennial groundnuts as a contained example of a “three sisters” garden.

Squash will quickly grow to fill a large pot and is likely to both grow as a short shrub (even the non-bush varieties) as well as cascade over the edge of the container (even the non-vining types). Because of this, it is a good idea to either place other decorative potted edibles in front of your squash or to select a receptacle that is tall enough that the base of it still shows off the glaze or pattern that you chose. Squash varieties are especially attractive in neutral colored containers such as a pale, spring green or matte white, but the deep yellow-orange blooms and various fruit shapes/colors also stand out in bright colored pots like cobalt blue or red.


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cucumber-pests-diseases

Section 7: Common Pests & Diseases of Squash

During (Indoor) Seedling Stage

Indoor plants and seedlings are more susceptible to certain pests and diseases than outdoor plants. Common problems you might encounter during the germination and seedling stage of your squash:

  • Aphids – Description: Small sap-sucking insects that proliferate on young plant stems and the underside of young leaves. Symptoms: Sticky leaves; curled leaves; weakened, limp or dying plants despite adequate water and nutrition. Organic Treatment: insecticidal soaps, horticultural oil sprays, organic insecticides (neem, pyrethrin, etc.). The more time you can get your seedlings outdoors, the less problems you’ll have from aphids. Aphids are a favorite snack for ladybugs, parasitoid wasps and other predatory insects.
  • White Flies – Description: Small, white flies that proliferate underneath leaves. Symptoms and Organic Treatment: Same as aphids (above).
  • Fungus Gnats – Description: Small dark-colored gnats; the small, white-colored larvae live in soil and eat the roots of young seedlings. Symptoms: Seedling growth rate slows and seedlings eventually die if untreated. Organic Treatment: For prevention, we’ve had success by mixing diatomaceous earth into our potting soil. For treatment after noticing a fungus gnat problem, we’ve had the most success by adding beneficial nematodes (specifically Steinernema feltiae or S. carpocapsae) to our potting soil.
  • Damping Off – Description: Death of young seedlings caused by fungal disease. Symptoms: Young seedlings wither and die, sometimes suddenly. Organic Treatment: Prevention is the best cure for damping off. Use a sterile potting mix; sterilize your reused seed trays before using them; occasionally water your seedlings with a 10 parts water: 1 part hydrogen peroxide mixture; don’t overwater; try to keep your seedlings in an area with good air flow; if a seedling or seedling tray gets damping off, immediately remove it from your seedling area.

After Transplanting Outdoors

Squash Diseases – The most common squash disease is:

  • Powdery MildewDescription: Any number of fast-growing, airborne fungal diseases. Symptoms: White powdery patches on leaves. Left untreated, powdery mildew causes the leaves to brown and dry out, eventually killing the plant. Organic Treatment: Powdery mildew can be easily prevented using organic methods. Make a mixture of milk and water (30% milk to 70% water is fine) and spray it evenly on the surface of the plants on a sunny day. Any type of milk will work, skim or whole. This method has proven to be as effective as any fungicide, although scientists aren’t quite sure how it works (likely antiseptic effect resulting from the sun burning the fungus as it’s bound by the milk proteins).

Squash Pests – There are a wide range of insects whose adults or larvae can cause significant damage to squash plants. The squash varieties that are least susceptible to these pest insects are the vigorous, vining Cucurbita moschata varieties that do not have hollow stems (hollow stemmed squash varieties are susceptible to vine borers).

squash vine borer eggs and larvae
Squash Vine Borers – If you live east of the Rocky Mountains, one of the most challenging pest insects to deal with are squash vine borers. To learn five ways to prevent or stop squash vine borers, please click here to learn more on our blog.

Pest Identification & Treatment – If you’re trying to ID a particular squash pest or figure out how to address the problem using organic solutions, Clemson University Extension has an excellent overview of the most common squash pests along with various organic prevention and management techniques.

As the Clemson University Extension website states—and we’ve found from our own experience—neem oil extract used as a foliar and stem spray is an effective treatment and prevention for managing virtually all squash insect problems, especially when combined with the other management techniques listed on their website. There is no consensus as to what harm, if any, that neem oil can cause to bees or other pollinators, but the general rule is to apply the diluted neem oil in the late evening after the bees have returned to their hives. Also, never apply neem oil directly on or in the squash flowers where the pollinators congregate.

Remember…

A healthy garden needs pests. Pest species provide food for beneficial species. A garden ecosystem that’s teeming with life will tend to hold the population of any one species in check. We’ve found that by focusing on improving our soil fertility and using polyculture plant systems that attract and support a wide variety of insects, we’ve virtually eliminated all pest and disease problems from our garden.

Please be thoughtful in your approach to these potential problems. Is your soil healthy and teeming with microbial life? Have you planted other beneficial plants throughout your garden system that might help with the problem? If you wait a few days, will the “pest” become the food of a predator? Observe your garden system and think holistically before taking any action that could disrupt the web of life (pesticides kill beneficial insects too, not just pest insects; fungicides kill beneficial funguses too, not just “bad” funguses; etc). Personally, we’d rather lose a plant than accidentally kill a colony of nearby bees or other pollinators.


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squash-harvesting

Section 8: Harvesting Squash

Ensuring Squash Pollination

Like other cucurbits, squash produce a few rounds of male flowers before they begin producing female flowers. Only the female flowers produce fruit.

There’s a good reason for this phenomenon: a squash plant wants to increase the likelihood the pollinators know its there before taking the time and energy to produce any female flowers. So, don’t be disappointed if every flower doesn’t turn into a beautiful squash. The majority of flowers a squash plant produces are male and can not produce fruit, only pollen.

How to hand-pollinate squash plants

If your squash plants are repeatedly producing female flowers, but not setting any fruit, it means you don’t yet have enough pollinators in the area to pollinate the flowers. Don’t lose heart! You can pollinate your squash plants yourself.

Here’s how: dip a q-tip into the pollen surrounding the anthers or a male squash blossom, then use the pollen-covered q-tip to pollinate the corresponding part of the female flower (the stigma). You can play the role of a bee until you notice more pollinators coming to your plants.

How to hand-pollinate squash flowers. 1. Taking pollen from a male squash flower using a q-tip, 2. Using the q-tip covered with pollen from the male flower to pollinate a female squash flower.

1. Taking pollen from a male squash flower using a q-tip, 2. Using the q-tip covered with pollen from the male flower to pollinate a female squash flower. Notice the miniature fruit at the base of the female flower, which is absent on the male flowers.

Coincidentally, this tip is also extremely helpful if you’re trying to get avoid cross-pollination and produce genetically stable seed (for seed saving) while growing multiple types of squash plants. More on that later…

When to Harvest Squash

Harvesting SUMMER Squash
There is no right or wrong time to pick summer squash. However, many gourmet chefs demand only the youngest, most tender squash (with the flowers still on) for their kitchens.

We’re not that picky and prefer to let our summer squash get some size on them before we pick them. If we’re trying to get mature seed for future years from a particular fruit, we’ll leave it on the plant for as long as possible.

Harvesting WINTER Squash
You can pick winter squash when they’re young and tender to eat just like a summer squash. However, if you want your winter squash to live up to their name and last you through winter as a storage squash, then you want to give the fruit plenty of time to mature.

It usually takes a couple of months for their hard, protective skin to fully develop. You’ll know they’re ready for harvest when the fruit has stopped growing in size, the vines become dry and the rinds have become leather hard. If you press your fingernail against the skin, it should be almost impossible to leave an indentation.

We’ve grown some heirloom storage pumpkins that have lasted for 2+ years and still been delicious when we finally baked them. Other winter squash varieties will only keep for a few months, so make sure you know the storage life of the variety you’re growing!

When harvesting summer or winter squash, it’s usually best to wear gloves so your hands don’t get scratched by the spiny stems and underside of the leaves. Use clippers to cut the fruit from the plant, leaving a couple of inches of stem on the fruit. You can sometimes twist off young squash, but you should never try to pull off the fruit as you can damage or uproot the plant.



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Section 9: Saving Squash Seeds

Saving seeds is an important part of being a full-circle organic gardener.

This critical step ensures that seeds are passed down from generation to generation, so please give it a try and also be sure to share your seeds with other people! Another benefit: seeds you’ve properly saved from your own garden will be better adapted to your specific growing environment via natural epigenetic processes.

You can save your new, open-pollinated squash seeds (don’t bother trying to save hybrid seeds) as follows:

Step 1. Avoid cross-pollination

Squash can be cross-pollinated by other squash varieties. So, to make sure you’re producing a true, non-hybridized seed, either:

  • Provide a 1/4 mile growing radius – Don’t grow any other variety of squash within at least a 1/4 mile radius (for commercially produced seeds, the rule is 1/2 mile), or
  • Be a Bee – (our preferred method) Before the flowers have opened, cover both a male and female flower of the same variety with a well-secured paper or plastic bag to prevent pollinators from cross-pollinating other varieties. (Female flowers are easily identified by their bulbous base which will eventually turn into a fruit.) Once the secured male and female flowers have opened, temporarily remove the bags and use a q-tip to extract pollen from the male flower and rub onto the interior of the female flower (see image in harvesting section above). Once you’ve pollinated the female flower, cover it back up with a bag until the fruit sets. Once the small fruit has visibly set, loosely tie a small string around the stem of the fruit so you can remember which fruit you’ve set aside for seed-saving.

Step 2. Select the healthiest fruit from the healthiest plants

Let your seeding squash sit on the vine for as long as possible (until the plant dies or a frost is imminent). If you’ve got several squash set aside for seed-saving and can afford to be a bit more picky, only save seed from your healthiest plants and fruit, and eat the smaller fruit from the less robust plants.

Step 3. Extract and clean the seeds

Once you harvest your seed squash, scoop or pour out the seeds into a strainer. Rinse under warm water, removing any flesh or stringy substance from around the seeds as you go.

Step 4: Dry, store, and label your seeds

Place the cleaned squash seeds on a drying surface that they won’t stick to. A ceramic plate, cookie sheet, or piece of wax paper works well. Label the drying plates if you have multiple seed varieties. Give your seeds at least two weeks to fully dry indoors, especially if you live in a humid environment like we do.

Once your squash seeds are fully dry, store them in an airtight container (add rice or silica packages to hold any moisture). You can also store the seeds in envelopes, although this will make them more susceptible to moisture damage over the course of several years. Again, be sure to label the seeds as you go so you don’t lose track of what variety you’ve saved!

How long do squash seeds last?

Properly stored, your new squash seeds can remain viable (e.g. able to be grown) for 4-5 years. Plant and share them so their grow journey continues!



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Section 10: Additional Resources: