Transplant time

Before you transplant your seedlings, it's a good idea to harden the young plants by exposing them to the outdoors for a few hours each day. 

It’s time to think about transplanting, and the first step is hardening off your plants so they survive the move from the protected shelter of your house to the rigors of your garden or greenhouse. Toughening up those babies begins a week to 10 days before you intend to set them out.

All that entails is gradually increasing the amount of exposure to sunlight and wind each day. I load all flats and containers on my gardening wagons, cover each wagon with a plastic gardening umbrella and roll them in and out each day. The first day it is just for a few hours in the shade. The next day, I put them in a spot where they will get shade for a few hours and then some sun when it rotates to that side of the house. The third day they are in sun all the time.

The plants that are going into the greenhouse, or into the beds that have plastic covers that will stay on until July, remain under the umbrellas throughout the entire hardening off process. The vegetables, flowers and herbs that will be in my outdoor beds with no protection, will lose the umbrellas after three days of being dragged in and out, so they get used to the wind. The first day the umbrellas will be taken off for an hour or two, but within about four days they will be going bare naked all the time. Whatever your style or timeline for hardening off, do check watering needs every day because the sun and wind dry out the soil faster than your grow lights did.

I know I am always referring to things like my wagons or umbrellas. However, there were many years when I didn’t have the money to spare for specialized gardening equipment. You don’t need wagons; I used to haul flats out one by one and put them on tables fashioned from saw horses and scavenged plywood, or even laid the flats on the ground. My plastic gardening umbrellas are wonderful but they are an extravagance it took me years to acquire; before they came along, I attached a rope between two trees and threw plastic over it to form a large tent to put the flats under. All of which is to say, do the best you can with what you have, but find some way to harden off your plants so they give you the best yield.

How I transplant has not changed much over the years, except that now I pace myself. The eight-hour binge-planting sessions are a thing of the past because a 20-year-old back is a thing of the past. I may think I am ignoring the twinges signaling that it is time to call it a day, but what really happens is that I start to work faster and faster. Soon I am practically gouging holes out of the ground like a mad dog, throwing in the plants and giving a final watering by using my garden hose like a water cannon that flattens everything in its path. The nice thing about slowing things down is that instead of being a chore to power through, transplanting has become enjoyable, almost meditative.

I start by thoroughly watering any seedlings I am going to transplant that day because their containers release wet soil easier than dry. While the roots are getting soaked, I dig the holes. Different varieties have different sized root systems, so I dig the size of the hole to match the plant. I want to have an opening large enough that the roots can be spread out, and so that when the dirt is back-filled the soil level will be not much more than an inch higher than it was in the seedling container or flat. If you intend to add something like blood or bone meal to the hole, you don’t want the roots to be in direct contact with it so dig down another inch put in the amendment and mix it around, and then cover with an inch or so of soil.

There are two major exceptions: indeterminate tomatoes and plants, like strawberries, with growth crowns that must be exposed or the plant won’t make it. Tomatoes can be buried right up to the top knot of leaves, and more roots will grow along the freshly buried stem. Before putting the stem under the soil, cut — don’t rip — off the leaves. Determinate tomatoes can be set in a little deeper than they were but do not treat them like vining indeterminates because their growth habit is very different. Determinates have a set size and yield, so stripping off and burying what would have been half of the height of the plant will reduce yield. Strawberries, on the other hand need to be set in very carefully, one might say shallowly, leaving the growth nub exposed. It is easy to see, look for a knob of bunched up leaves.

After all the holes for that day are dug, I fill them with water; by the time I get to actually setting the plants in the water will have soaked into the ground. I handle one seedling at a time because their tiny roots can dry out if you pull them all out and let them lie there exposed to the air while you monkey around. I put the plant in, spread out the roots a bit, back fill with soil and press down so that all air pockets are eliminated. This also will create a small bowl around each plant so when you water it will be funneled directly to the roots rather than running off into the aisles between your rows.

The truth is bowls work really well for a few weeks. Then, just as the foliage is getting so large that you have problems seeing the main stem where you need to direct the water, the sides of the bowls level out down to the soil so you end up with no bowls. So, now, at the time of transplant I put in season-long bowls.

Mine are made from those black plastic containers that housed various bushes I bought from local nurseries. They aren’t good for much else, being too large for seedlings and too small for a container crop, so I repurpose them. The bottom third of each pot gets chopped off and the resulting cylinder is pushed in around my larger crops, such as dahlias and pumpkins. I bank dirt up against the outside and now the plant is a nice sturdy bowl sticking up about five inches out of the ground.

Not only do these bowls direct the water to the roots, they give me an indication of how much water I am giving the plant. I am by nature a person of extremes, so I tend to overdo everything. Having something that tells me enough is enough helps keep my watering under control.

To review, I dig holes, add any amendments and cover with an inch of soil, fill the holes with water, set in and gently spread out the roots of each plant, back-fill, and pat down to make a bowl or push in the plastic cylinders.

Only then, for the first time, do I water the plants in their new homes. Days before transplanting, I fill 33-gallon trash cans with the ice-cold water that comes out my hose. By transplant time, this water has warmed up to a comfortable temperature, so I use gallon milk jugs to ferry this water to each transplant, adding half strength fish fertilizer to the water before gently tipping in the liquid at soil level. Watering from above the plant is hard on the stems, and if the leaves don’t dry out before the cooler night you could end up with diseases.

Finally, I walk by each transplant to make sure that the soil did not develop sink holes; if it did, I add more dirt and water again. Then I congratulate myself on a job well done and go inside to remind my husband what a hard-working wife he has.

Linden Staciokas has gardened in the Interior for more than two decades. Send gardening questions to her at