Bring Tomatoes to Your Spring Garden

Use the right variety, timing, and careful planning to plant tomatoes in your garden late in the spring.

Planting tomato seedlings

Handle seedlings very gently. If you must touch them, handle them by the leaves, not the stem.

Photo courtesy of www.RareSeeds.com

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Many home gardeners seek bragging rights for bringing in the first ripe tomatoes of the season, but very few have a detailed plan for doing it. Here’s what you need to know to bring in the earliest possible tomatoes in your region, in a way that requires the least work. In fact, in less than an afternoon, you can create a tomato patch that will swamp you with fruit all season long without weeding, or even very much watering.

Tomatoes are among the highest yielding of all our garden crops, but the earliest tomatoes—those that grow and produce well when the spring weather is still cool—are not the most high-yielding types. So we need a strategy.

Let’s start with the soil. A very rich soil — that is, one with an abundance of nitrogen from compost or manures — tends to flush tomato plants into lots of stem and leaf growth, but not so much into producing tomatoes. In trials at the Rodale Institute in Pennsylvania, we grew tomatoes in pure compost, in soil under turf that was removed, and in unimproved field soil that had been in continuous corn crops where agricultural chemicals had been used for many years. The tomatoes produced the heaviest crops in the soil that had been under the turf. Circles of turf grass were removed and tomato plants put into the exposed soil underneath. This seemed to suit the tomato plants best, prompting them into good, compact growth with lots of fruit.

If you have an area of your garden that’s 12 feet by 8 feet (96 square feet) and covered in turf grass, lift six 3-foot circles of turf and shake the soil from their roots back into the exposed soil, making two rows of three circles each. If the soil is bare or weedy, remove any weed roots and improve the soil nutrition with about a square foot of good compost per circle. This is where your tomato garden will go.

Varieties

You are initially after the earliest possible tomatoes in your area. And so, you need seed of early varieties—those that will mature fruit when other varieties are hanging out, waiting for warm weather. But if you’re like me, you’ll also want a variety that will produce pounds upon pounds of tomatoes for sauce during the warm summer months.

First, you need to understand the difference between determinate and indeterminate tomatoes. Determinate plants set a large crop of tomatoes and then stop growing. Indeterminate plants keep producing new stems throughout the growing season, right up to frost, with trusses of flowers followed by fruit emerging from the leaf axils of those stems. For our earliest tomatoes, we’ll choose one determinate variety. The other variety in our six-plant tomato patch will be indeterminate. We will also grow an extra indeterminate plant in a large pot to replace our earliest tomato after it sets its crop of fruit. Here are some varieties I recommend:

Purchase a packet of Oregon Spring and a packet of a large paste tomato like Rocky. Oregon Spring is an open-pollinated, cold-tolerant tomato developed at Oregon State University for home gardeners along Oregon’s cool coast. The catalogs rate it at 58 days from setting plants in the garden to maturity of its first tomato crop, but we can hasten that. Or choose Stupice, rated at just 52 days. Large paste tomatoes like Rocky — or old favorites like San Marzano or Roma — are indeterminate and will produce bushels of fruit all summer. Rocky is good because each tomato is large and can be used fresh as a slicing and salad tomato or it can be used for sauce. All these varieties (and many more) are available from Tomato Grower’s Supply Company, and TomatoFest

As you prepare for the growing season, start saving all your newspapers and 1-gallon plastic milk or water jugs (you’ll need 18) — there’ll be a good use for them later.

Setting up the tomato patch

Identify your last frost date. In much of the country, that’s about May 15, with more northerly areas up to several weeks later and southerly areas up to a month earlier. Most tomato-growing instructions tell you to wait until two weeks after the last frost date to plant your tomatoes, but I’m going to tell you to plant them two weeks before the last frost date. After all, we want the earliest possible tomatoes and I have a strategy for getting the plants to produce fruit while the neighbors are still selecting their seedlings at the garden center.

Determine where your tomato patch will go. It will be two rows of three plants each for a total of six plants, which translates to a width of 8 feet and row length of 12 feet, or 96 square feet. At the hardware store, buy five pieces of 8 x 12-foot clear plastic sheeting. You’ll use one piece to entirely cover the area. Reserve the other four pieces for later use, which I’ll describe under “Getting Early Tomatoes.”

About 6 weeks before your last frost date, lay the single piece of clear plastic over your future patch site and shovel a little soil along the edges so heat is trapped under the plastic and breezes can’t blow it away. This will help warm the soil long before the surrounding soil is warm. If there are grasses and weeds, mow them down almost to ground level before putting on the plastic.

Starting your plants

About the same time you are laying down the plastic, start your tomato seeds. If you have a cold frame, warm porch, sunny bay window, or any area that gets 6 hours of sun a day, place your new seedlings there. If not, consider investing in fluorescent grow lights hung just a few inches above your seedlings. Tomatoes like heat and light.

Rather than use pots, you’ll need a series of paper cups — small, medium, and large. With a pencil, punch three drainage holes in the bottom of the smallest cups. Fill the small cups to within a half inch of the top with potting soil, starting mix, or any good garden soil. Plant two seeds of each variety of tomato in each cup. Plant two or three cups with Oregon Spring or Stupice and about 12 to 18 cups with your high-volume paste tomato, such as Rocky, marking the cups so you know which variety is in them. Place the cups in a containing tray that won’t leak and water them well. You are planting a lot of extras because you’ll want to select the strongest and largest seedlings to actually plant later in the garden.

The new seedlings will show two leaves — the cotyledons — at first, and then will follow with true leaves with scalloped margins. When the seedlings show four true leaves, take the next larger-size cups and punch drainage holes, then fill them with potting soil. Select the largest and strongest seedling from each of the smallest cups and transplant it to the next larger size, burying the stem to just below the true leaves. Handle the seedlings very gently, pricking them free with the tines of a fork. If you must touch the seedlings, handle them by the leaves, not the stem. The baby tomato can produce new leaves if you accidentally damage one, but not a new stem. Nick off the cotyledons with a fingernail or use scissors. Discard the runts and mark the new pots with the variety in them.

Let the tomatoes grow until they now produce a tuft of six to eight new leaves at the top of the plants. Take the next larger size of paper cup and repeat the procedure, again nicking off lower leaves and burying the stem right up to the tuft of new leaves at the top.

Tomatoes produce roots all along their buried stems, and so what you’ve been doing is creating a tomato plant with a small but strong tuft of growing leaves and a great big ball of roots. If you’ve ever purchased started tomato seedlings at a nursery, you’ll notice that they most likely have long stems and lots of leaves but very small root balls. This is because the nursery has been feeding the plants with high-powered liquid fertilizer, so the plant has no need to grow lots of roots. It’s swamped with fertilizer. When such a plant is put into the garden, suddenly it no longer gets copious quantities of fertilizer, yet it has all those stems and leaves to support without enough root system to support them. And so it sulks and hardly grows at all for a few weeks to a month, until its root system catches up with its green tops. But here you have created exactly the opposite: a huge root ball and very little top. When this baby gets planted, it takes off like a rocket, with plenty of roots to supply immediate growth of strong stems, greenery, and of course, big tomatoes.

Planting the tomatoes

For your six plants, you’ll have one Oregon Spring or Stupice and five plants of your main, indeterminate variety like Rocky. The sixth indeterminate plant (Brandywine is a delicious choice, available from Baker Creek Heirloom Seed Co., 866-OLD-SEED) should go in a 5-gallon pot, staked to grow there until Oregon Spring is finished, after which you’ll pull the Oregon Spring and transplant the sixth main crop plant into its space.

You can leave the clear plastic on the ground and punch planting holes through it, but I don’t recommend that. Over the summer, it will tend to break apart due to foot traffic and create a mess. So I advise pulling up the plastic at this point and storing it for later use, as you will see. Dig six circular holes a foot or more deep and a foot across. If the soil is very poor and you are not removing turf, add a cubic foot of compost to each hole before putting in the tomatoes and mix it with the native soil. Plant them deeply enough that all of the root ball and most of the stem is buried. Run a hose on each plant on a slow trickle for at least a half hour, so they are thoroughly watered in.

Mulching the plot & caging the tomatoes

Each tomato plant will need a vertical cylindrical wire cage to which you can tie the elongating shoots. Tomatoes left to lie on the ground will rot. The wire mesh should be generous enough for you to reach your hand through the squares in order to harvest the tomatoes inside. Concrete swimming pool reinforcing wire (reinforcing mesh) is ideal. It will never rust out and your hand will easily slip inside the squares formed by the wire mesh. You’ll need six cages, each made from 9 feet of 4-foot-wide wire mesh formed into a circle slightly smaller than 3 feet in diameter. So you will need at least 54 feet of wire mesh, 4 feet in width, cut into six 9-foot lengths. Let’s say 9 1/2-foot lengths (57 feet in total), because you’ll need a little extra to form each into a circle and crimp the exposed wire ends onto the closest wire square to make each cage. This reinforcing wire is tough stuff, so you’ll need a good pair of vise grips and gloves for this work.

Once the cages — six cylinders 4 feet tall and about 3 feet in diameter — are constructed, it’s time to gather up all those newspapers you’ve been saving. Lay thick pads of newspaper on the ground over the whole tomato patch, exposing only the holes with the tomatoes in them. Use stones to hold the edges of the paper down so they don’t blow in the wind. This newspaper mulch, if good and thick, will positively prevent weeds from growing in your tomato patch, and it will hold moisture in the ground so watering will be kept to a minimum. Newsprint will decay over the summer and you can turn it into the soil at fall clean-up, where the wood fibers in the paper will decay into a crumbly brown mass that will loosen the soil and hold water like a sponge.

Once the patch is covered with thick pads of newsprint, set one of the cages over each tomato plant. Weigh down the bottom edge of the wire with several heavy stones or bricks in at least three evenly-spaced places so the cages won’t topple over in a wind, especially after the tomatoes grow up to fill the cages and they become top heavy. I’ve also used tent pegs driven around the bottom wire of the cages to hold it firmly to the soil. 

Finish the patch by covering the newsprint with good-looking mulch like sphagnum moss, spoiled hay, cocoa bean hulls, fir bark, or any other organic material. This top dressing looks good, makes it easier for you to walk on the spaces between the plants, covers the papers so they don’t blow around in the wind, and will decay so it can be turned into the soil with the newspapers to add organic matter at fall clean-up time.

Getting early tomatoes

Remember that we just planted our tomatoes in pre-warmed ground long before the last frost date. Now here’s how to keep the plants warm so your tomato production begins as soon as possible and you can harvest ripe tomatoes even in June!

You will need three plastic, gallon-sized water or milk jugs for each plant. Fill them with water and set three of them around each seedling inside the cage. There should be just enough room for the three jugs and the seedling growing up between them. This water acts like a thermal flywheel, absorbing heat during the day and giving it off to keep the plants warm through the night.

Additionally, retrieve the clear plastic you used to warm the soil. You will need six pieces, each 4 x 12 feet. That 8 x 12-foot piece of plastic you used to warm the soil will give you two of these pieces if cut down the middle lengthwise, and you’ll need four more to wrap all six cages. This is where two of the extra pieces of 8 x 12-foot plastic come in handy. These, also cut down the middle, will provide pieces to wrap around the outside of the wire cages with some extra for overlapping to make the wrapping snug. Duct tape the overlapping edge from the top of the cage down to the soil level and add a few pieces of duct tape along the top edge, so the plastic won’t slip down.

You now have two 8 x 12-foot pieces of plastic left. Cut each into three 4 x 4-foot pieces of plastic, giving you six pieces to cover the tops of the cages. Lay one across the top of each cage and hold them in place by lengths of scrap wood or some weight like rebar — anything other than duct tape. The tape will be too difficult to remove without tearing up the plastic, and you will be taking off and putting back this top piece of plastic during the early part of the growing season.

You’ve now created mini-greenhouses for your plants. Be aware that as days grow longer and the sun hotter, it could get too hot inside these cages. Place a thermometer in one to check the temperature of all. About 90 degrees F should be the maximum inside the cages. On bright sunny days, you can remove the top plastic, putting it back on as the sun lowers in the west.

Once you reach your last frost date, consider removing the tops permanently and by two weeks after the last frost date, remove the plastic from around the cages. Empty the jugs and store them under a tarp, strung on a wire in the rafters of a shed, or under some other cover, as direct sunlight will degrade them, and so you can re-use them each year.

Where the last frost date is May 15, your tomatoes will be well on their way to maturity, especially Oregon Spring or Stupice. They should deliver home-grown, ripe tomatoes of good quality to you by the end of June or thereabouts.

Summer maintenance

It doesn’t take a lot of time to set up this patch and from now on, it takes almost no time to maintain. Make sure the tomatoes have adequate water, usually a deep watering once every 2 or 3 weeks in the summer with little rain, or less where rainstorms are frequent. The plants have all the nutrition they need. Weeds won’t be a problem as you’ve covered the ground with a thick mulch of newspaper sections. You’re good to go.

Your tomatoes can be gently and loosely tied to the wire cages as they grow, and some indeterminate varieties may grow past the top. Rather than letting them tumble over the edge, weighed down with fruit, which can damage the stems, you can drive three 8-foot stakes into the ground spaced evenly around the outside edge of each cage, then continue tying the elongating stems vertically to the stakes.

Your biggest tomato expense will be for the wire cages, but they will last a lifetime, and if you’re really pinched for funds, less-expensive types of wire are available. Mulch for the surface of the patch isn’t very expensive, and tomato seeds, paper cups, potting soil, and clear plastic are cheap. Newspapers and empty water or milk jugs are essentially free since they’ve already served their primary purpose.


Jeff Cox is the former managing editor of Organic Gardening magazine. He’s the author of The Organic Cook’s Bible, which won a James Beard Foundation nomination as Best Reference in 2007. Jeff is also the author of 18 other books on organic food, wine, and gardening. He currently blogs at www.organicfoodguy.com.