Tomatoes in Small Places

omato season! Nothing gets the blood of a gardener flowing like the arrival of another gardening season and the promise of vine-ripe tomatoes! Can’t you already taste them? Whether you are an old pro or a novice wishing to start your first garden, the lure of tomatoes is likely to be on your mind as you make spring planting plans.

Not everyone has room for a traditional garden plot. The average American lot size for most new neighborhoods has shrunken to the size of a postage stamp. If you live in an older neighborhood your lot is most likely covered by giant spreading trees that prevent most of the sunlight from reaching the ground. Townhome and apartment dwellers, on the other hand, have little to no soil space in which to plop a plant.

For all the above folks container growing offers a great way to enjoy growing the queen of the vegetable garden. Even though I have quite a large “traditional” garden, I like to grow a few container tomatoes each year. So, in addition to the standard tomato patch out back, I just gotta have a few more plants in containers.

Let’s take a look at some simple factors that lead to successful tomato production in containers.

Container Selection

The bottom line when it comes to containers is really quite simple. A container needs to hold enough soil to make watering and fertilizing less frequent and to provide good drainage to prevent soggy soil conditions. That’s pretty much it. With this in mind, there are more options for container growing than you can imagine.

The best container size depends partly on the size of the mature plant. Dwarf and determinate varieties require less soil volume than an indeterminate variety, for example. Choose a container that holds at least 5 gallons of soil. More is better. The smaller the soil volume, the more often you will have to water and fertilize in order to maintain good plant vigor and health. Don’t forget that in hydroponic systems where water is constantly available and nutrients are in a continuous, balanced supply, no soil at all is needed.

However, on your patio with the sun shining down on the plants, if the soil volume is less than 5 gallons (approximately .67 cubic feet) you will likely be watering twice a day to prevent serious drought stress. Whenever possible, choose containers that hold 10 gallons or more of soil for a more resilient growing setup and greater productivity.

Traditional containers work great. I like the new lightweight polymer containers that look like stone, terra cotta or other attractive materials but weigh only a fraction of the weight of these other materials and cost much less, too.

I also really like non-traditional container choices. Remember, soil volume and drainage are the keys. Some of my favorites include half whiskey barrels, 5-gallon buckets, galvanized tubs, water troughs and wheelbarrows. An old wheelbarrow with some holes drilled in the bottom to facilitate drainage makes a great planter. Consider the fact that you can easily move it around to the sunniest spot on the property and move it into the garage when a frosty night is forecast.

For the lover of novelty a recent innovation is the “hanging tomato” container. These are pots of soil that have a hole in the bottom into which a transplant is planted. The tomato roots grow up into the pot and the plant hangs down!

Gardeners can now purchase special pots or bags for such a system. I made my own hanging container last year using a 5-gallon bucket. I cut a 2-inch hole in the base, just large enough to work the foliage of a small transplant through. Then I wrap the stem just above the roots with wet newspaper or an old cloth rag to serve as a plug in the hole. Next fill the container with soil and water it in well.

Find a sunny spot and a means of support for the hanging tomato planter and you’re in business! As an added touch I planted basil in the top of the 5-gallon bucket. It’s decorative and just seems like the right culinary choice to grow with the tomato!

In addition to pretty pots and strange containers we need to include “no containers at all”! Take a section of mesh wire about 5 feet long and 2 feet tall. Bend it into a circle and secure the ends together to form a cylinder about 20 inches in diameter and 2 feet tall. Line the interior sides with about 6 sheets of newspaper as you fill the cylinder with potting soil. Then plant a tomato in this temporary container.

A similar approach is to punch a dozen holes in the bottom of a trash bag and then fill the bag about 18 inches deep with potting soil to create a temporary container. Still another easy option is to purchase potting mix in a 1 or 2 cubic foot bag, punch a dozen holes in the back of the bag and then lay it on the ground with the holes down. Then cut a 6-inch “X” in the middle of the front (now the “top side”) and plant a tomato plant in the potting mix. The bag serves as a great temporary container for the tomato crop.

Another option is to create a raised bed with timbers, cinder blocks or stone and fill it with soil for growing tomatoes. In essence this is a large container and works great for folks with no sunny place other than an asphalt or concrete driveway or patio. Just make the bed 18 inches to 2 feet deep and your tomatoes will thrive.

Growing Medium

I’ve already made the point that the volume of growing medium is important to prevent stressing the plants. The quality of this medium is also important. The best results in container growing are achieved in a mostly soilless medium. Soil is fine for the garden but in a container where roots are especially limited, potting soil will usually give better results since its ability to hold moisture, drain well and hold nutrients are all outstanding.

Choose a growing mix with medium texture. Too chunky and it dries out too fast. Too “mucky” and it doesn’t drain well, sinking into a soggy mess. Keep in mind that perlite and vermiculite help improve drainage in a mix while garden soil, peat moss and compost tend to hold moisture well. I like to screen some of my compost through 1/4 inch hardware cloth and then mix 4 parts compost with 1 part garden soil and 1 part perlite to create a nice, fine textured mix. That said, I see a lot of variation in growing mixes and most do a great job. Do some experimenting to come up with your favorite blend.

Don’t bother adding gravel or pot shards to the bottom of the container. This old recommendation does not help drainage and only limits the depth of growing media for plant roots. I realize that this misguided recommendation refuses to die in gardening literature, but trust me, it is neither helpful nor necessary.

Well-Adapted Varieties

There are more tomato varieties than stars in the sky and any variety that will grow in your garden will grow in a container if there is adequate soil volume. You should select varieties based on what does well in your area.

You’ve probably heard and read a thousand admonitions to select varieties with a VFN after their name to provide natural resistance to some soil diseases and to nematodes. Container growing may be an exception to this rule, especially if the medium is a soilless one. A good, fresh, disease-free medium negates the concern of these and other soil borne diseases.

One factor in cultivar selection is to consider the mature size of the plant. Determinate types reach a given size and terminate in a bloom cluster while indeterminate types continue vining and setting bloom clusters. Both can be grown in containers provided you have some trellis or cage system for supporting the plants.

Determinate types are smaller in stature and often preferred for container culture for this reason. There are also a few semi-dwarf and dwarf types such as ‘Tiny Tim,’ that will grow in a large hanging basket. The dwarf types are novel but not as productive as a good determinate, semi-determinate or indeterminate variety.

I always like to experiment with a few new varieties each year but depend on the proven ones. A few of the many cultivars that have performed well for me include the following. If you want a slicing type tomato I suggest you try:

Determinate: ‘Bush Early Girl,’ ‘Celebrity,’ and ‘BHN 444’;

Semi-determinate: ‘Amelia,’ ‘Better Bush’;

Indeterminate: ‘First Lady.’

Paste type tomatoes are well worth growing even if you aren’t making sauce or canning tomatoes. I actually enjoy them for fresh eating because they are meaty and have smaller seed cavities with a minimal amount of the jelly-like substance surrounding the seeds. Some varieties to consider include ‘Roma’ and ‘Viva Italia’ (both determinate).

Small-fruited tomatoes are not so picky about setting in the heat, although the skin gets rather tough when the temperatures rise. The following small-fruited types are all indeterminate unless noted otherwise:

Grape types: ‘Sugary,’ ‘Agriset,’ ‘Sweet Olive’ (determinate), and ‘Juliet’ (large grape type);

Cherry types: ‘Sweet Million’ and ‘Tiny Tim’ (determinate; plants only 18” tall);

Large cherry types: ‘Sweet Baby Girl’ (compact indeterminate growth habit) and ‘Sweet Chelsea.’

Find A Sunny Location

The container needs to be in an area that receives a lot of sun, 6 hours at a minimum. Morning sun is best. A little late-day shade is fine and may be helpful when the full brunt of summer arrives. You may find that even with moist soil the plant wilts a little in the heat of a summer day and recovers when the sun goes down.

I don’t have to tell you how hot a Texas summer day can be and the demand put on the plant to transport water fast enough to keep up with the water lost in the leaves. This reinforces the need for a sizeable container and for placing the plant where just a little mid- to late day shade can lessen the demands. Make sure that there is a source of water nearby to make it easy to maintain even soil moisture.

Sometimes strong winds can blow a tall plant over, especially if the container is narrow and the growing mix dries out. In such cases a semi-protected location or means of anchoring the plant will be helpful.

Provide Support

Determinate cultivars can be supported with stakes or the wire plant holders that push into the ground while a plant is still young and small. These cultivars are the most well suited to container growing. Semi-indeterminate and larger types need even more support for the growing, soon to be fruit-laden vines.

A 5-foot section of concrete reinforcing wire bent to form a cylinder makes a 20-inch diameter tomato cage, which is about right. Another option is to place the container near a lattice or other secured vertical trellis. Then as the plant grows, lift and tie the lengthening vines to the support.

The simplest option is no support at all. Simply allow the vines to trail over the sides of the container. This takes up space and if the container is on the soil may contribute to some fruit decay diseases, but is not a bad option in many situations.

Tomato Care

Containers dry out fast, especially in the heat. They will require watering every day and in some cases where the plant is large, the container marginal and the area sunny, twice a day. If you allow the plant to go into drought stress, even temporarily, production will be decreased. Another result is that the condition known as blossom end rot (BER) will appear.

BER is caused by a lack of calcium reaching the tip of the fruit. When the cells in the tip of the tomato lack calcium during growth, they die and the black decay you see follows.

You may have adequate calcium in the soil but still get BER due to soil moisture fluctuations (from wet to dry). I have noticed that BER is worse on the first tomatoes of the season and tends to not affect later fruit as long as the soil volume and the nutrient content is adequate.

Unlike their garden-grown counterparts, container-grown tomatoes are getting all their water and nutrients from the limited confines of the container. Therefore this growing medium needs to be well supplied with nutrients to support the rapidly developing plant.

Start by mixing a slow-release product in the growing medium at the label rate to provide a bank account of nutrients for the plant. Then for an added boost, fertilize your plants with a soluble fertilizer solution at the low “constant feed” label rate every time you water or at the regular rate weekly.

An alternative is to sprinkle 2 tablespoons of a complete fertilizer on the surface, scratch it in to the top inch of growing medium and then water it in well. Repeat this every 2-3 weeks.

Like garden plants, your container tomatoes will benefit from some pruning, especially early on. Staked plants are usually trained to one or two main shoots. Remove the suckers that form at the stem at the base of each compound leaf. Caged plants will benefit from some early sucker removal. Leave only a few shoots to grow and produce. As the plant gets larger you can stop removing these shoots and allow the plant to fill and overflow the cage or trellis.

Container plants are subject to the same foliage diseases and fruit rots as garden tomatoes. Likewise aphids, mites and caterpillars are potential pests. Keep an eye out for such problems and take early action to prevent them from affecting production.

Tomato season is upon us, so consider growing a few tomatoes in containers this year. Then send us your comments and photos telling how it turned out!

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