by Eliza Holcombe Lord, Master Gardener, Master Naturalist, Permaculturist
May 2016 Tip of the Month: How to Get Your Young Garden Plants Established With Proper Irrigation
What are the #1 and #2 reasons that people unintentionally kill their seed starts or seedling transplants? Too much watering or too little watering.
Like Goldilocks, plants prefer things just right. (Nope, plants don’t like porridge.) If you only remember one thing from this article remember this: whether you’re starting seeds, transplanting seedlings, or getting your plants “established” in their final spots in the garden, their soil should feel like a well wrung out sponge: damp but not wet.
Now, let’s dig a little deeper to help you become a better gardener…
What Does It Mean to Get a Plant “Established”?
Have you ever moved to a new place? At first, it doesn’t quite feel like home. You don’t have your routine down. You don’t know where to eat out, shop for groceries, hang out, etc.. After a while, your once-foreign environment starts feeling comfortable and normal. You’ve got your route to work; you’ve got a favorite restaurant; you’ve got friends. You’re established.
The same thing is true with plants, except to “put down roots,” plants literally have to put down roots. Plants get established in their new homes via their roots growing into the surrounding soil and by forming symbiotic relationships with various microorganisms in the soil which feed and protect them and get fed via the plants’ root exudates in return.
How long does it take for a plant to get established? It depends, but under ideal conditions, here are some general guidelines:
- Perennial Plants (def: plants that live for more than two years) – Perennials are like the tortoise versus the hare. They’re in no rush. They’re slow to get established, but once they do, they might well outlive you. Perennial plants’ roots are established after about one year. After that, you might not ever have to water a perennial plant again if you live in an area that gets regular rainfall.
- Annual Plants (def: plants that don’t live past one year) – Annual plants are fast-growing and get established much more quickly than perennials, since they have to grow and reproduce very quickly. Annual plants’ roots can get established in as little as 6 weeks. Once established, you don’t have to be as concerned about tending to their watering needs, but this doesn’t mean you should neglect the plants at this point, especially during periods of extreme heat or drought.
What Can Keep Your Plants From Getting Established?
Here are factors that can keep your plants from getting established or even kill them:
- Too Much Water – Plants are not fish. Unlike aquatic plants, garden plants need aerobic soil conditions (e.g. oxygen to be present) and relationships with aerobic bacteria, aerobic fungi, etc to live. When you overwater plants, the soil gets soggy, which creates anaerobic conditions. This means that oxygen can’t reach the roots, aerobic microorganisms start dying and anaerobic bacteria start proliferating. Eventually, this causes the plant’s roots to rot and the plant to die. (*In hydroponic systems, plants form “water roots,” which are a different type of root than soil roots; also hydroponic systems keep the water in motion in order to maintain oxygen flow and nutrient flow over the water roots.)
- Too Little Water – Again, the ideal soil moisture level for plants feels like a well wrung-out sponge. This is the moisture level you want to have whether you’re starting seeds indoors, direct sowing them outdoors, transplanting seedlings, or trying to get your young plants established. Your finger is a great tool to use here and with a bit of experience, you’ll know exactly what your soil should feel like (wrung out sponge, wrung out sponge!). Just stick your index finger about 2″ down into the soil near your plants.
- Not Watering In Seedlings Immediately After Transplanting – Immediately after you put your transplants into their final spots in your garden, water them heavily in order to: 1) make sure their roots are making contact with the soil they were just transplanted into, and 2) be sure that both the roots and the soil are nice and moist to encourage the roots to grow into the new soil. Also, be sure the root ball of your seedlings isn’t sticking out from the soil. You want your transplants to be buried in their new soil up to the same level they were in your seed trays – or in the case of plants like tomatoes that have adventitious roots, you can even bury the stems. (Warning: burying the stems of plants that don’t have advenitious roots will kill them.)
- Poor Irrigation Maintenance – You’ve put your nice healthy seedlings into your garden and watered them in. Yay! But then you don’t get any rain for the next two weeks and it’s hot and windy outside. That means you’ll need to continue watering your seedlings at least several times per week until the plant is established (or perhaps daily if you till your soil, which decreases its moisture retention properties). If you get good 1/2″ or heavier rains a couple times each week, you might not need to do any extra watering. If you’ve direct-sown seedlings in your garden, some varieties may need daily watering until they’re about 2″ tall (smaller seeds like kale and lettuce come to mind, whereas larger seeds like beans and squash aren’t as needy.) Check the soil with your finger to find out! If possible, try to use drip irrigation rather than overhead sprinklers to prevent water evaporation/loss and reduce the likelihood of plant foliar diseases.
If your plants are established and you get good rainfall every week or so, you might not have to do any additional watering. If you want to maximize your soil’s ability to absorb and retain water, read our March 2016 Tip of the Month!