Growing your own transplants has multiple advantages:
- You can grow the exact varieties you want, not whatever’s available at the garden center.
- If — as I do — you live in a different zone than the town in which the garden centers are located, you can have seedlings available when your climate is ready for them. In my case, I’m either zone 7 or zone 8, depending on the microclimate, while the garden centers are catering to folks in zone 9. If I tried to plant garden center tomatoes, odds are I’d lose some or all to a late frost.
- You save a bunch of money growing your own.
- One of the most important aspects for me, however, is that you lose very few plants to transplant shock.
Plants grown for mass production are often forced — pushed to grow faster so they will be most appealing for the garden center trade. Almost invariably, that means the seedling is pot-bound by the time you buy it. Even if you run straight home and transplant it, it’s going to suffer some degree of transplant shock. Plants in flats have intertwined roots that must be cut to get the plant out of the flat; again, the plant suffers in the process. The classic way to transplant is to remove the plant from the pot and spread the roots out in the new soil to help alleviate the fact that it’s pot-bound. The tiny root hairs are damaged in the process, no matter how gentle you are.
Spring weather on our place is extremely variable; we’ve had hard frosts as late as May 29th, snow in April and 90-degree days in May. Small transplants often don’t handle those extremes well and I may lose the whole lot. I try to grow lots of extras for just that reason, but sometimes it means I have to keep growing on to larger and larger transplants. Or the early plantings take longer to mature than I expected, so my succession planting schedule takes a hit. So I developed a method that allows me to transplant even large seedlings — I’m talking 12- to 18-inch tall tomatoes, with a few blossoms on them.
The first thing you need is a large collection of starter pots. These need not be anything fancy. I’ve used recycled pots from yard sales, leftover seedling pots given to me by people who patronize garden centers, yogurt and sour cream containers scavenged from various sources and tin cans with holes punched in the bottom. I start most of my seedlings in the tin cans, because I have lots of them. Although you can get by with square pots, this method really works best with round pots. Fill the pots with potting mix or a really good loose, loamy soil. Plant up to five seeds about one inch apart in the center of the pot. Treat them as you would any other starter plant — water, sun, greenhouse, whatever you would normally do. Once the seeds germinate, give them a week or so to grow and then thin to the best one of the group.
Let your plant continue to grow. If something happens to delay transplanting into the garden and the plant is outgrowing its pot, move it into a larger pot. Choose a pot that will allow at least one inch of new soil all around. If you’ve used a 16-ounce yogurt container, for example, a gallon pot should be just the right size. Put enough rich soil into the new pot to plant your seedling at the same depth it occupies in the current pot. Tomatoes are an exception — you can plant them deeper if you remove leaves that would be under the soil, and they will root along the buried stem, making for a sturdier plant. You want the soil in the old pot to be damp but not dripping. Gently tap the edges of the pot with a trowel. Turn the seedling over and gently tap the bottom of its pot. It will almost always slide out with soil and root ball intact. Set it in the new pot and gently fill in with soil around the edges. Firm it by pressing gently around the plant stem. Please note the repeated use of the word “gently” here. Remember, you’re trying to protect those fragile root hairs.
When you’re ready to move it to the garden, dig a hole in the soil about one inch larger than the diameter of the current pot. Fill the hole with water and let it soak in. Repeat. Tap the sides of the pot (yes, gently) all around to loosen the soil. Now, upend your plant and tap the bottom so it will slide out. Center it in the hole and gently fill in the sides with new soil, tamping it carefully with your trowel — you don’t want any air pockets. Press the plant gently into its new home. Water the surrounding soil — a gentle spray works best.
I have transplanted plants even on days when the weather forecast was for 100-degree weather the next day. My transplants have handled the heat in stride with no signs of transplant shock and gone on as if they had never been moved. When you’re using succession planting because of limited space or if you’ve had to delay transplanting for some reason, this system has major benefits.