Based on our 2008 and 2009 trials, there are some great tomato varieties that are easy to find in seed catalogs and garden centers that will help you start growing tasty tomatoes. This fact sheet coupled with the advice in “Growing Great Container Vegetables #1: General Recommendations”, should get you on the path to success.
If you want to grow these types of plants in your garden, you might have to look for a greenhouse that does so or start the plants yourself. Look for varieties that are labeled “compact” or “for containers”. Larger garden varieties, even those that are thought to be determinate, will simply get too tall for a container and need too much support. In our trials, we looked for varieties that required little to no trellising. Unfortunately, only a few varieties have required no support.
Growing juicy, flavorful tomatoes is a rewarding experience for any gardener With the right conditions, tomatoes can thrive in containers on a balcony, patio or deck Choosing the proper size container is essential to give tomato plants the root space they need to grow and produce fruit. This article will explain what size container is best for growing tomato plants.
Why Container Size Matters
Tomato plants have expansive root systems that need room to spread out and take in water and nutrients. Small containers restrict root growth, resulting in stunted plants and reduced yields. Tomatoes are heavy feeders, so their roots need sufficient soil volume to supply the plant with nutrients throughout the growing season.
Bigger pots equal bigger plants and more tomatoes! The larger the container, the more soil it can hold and the larger the root system and plant can become. A large container size also helps buffer against drying out too quickly.
Minimum Recommended Container Sizes
As a general rule, a 5-gallon bucket or pot with equivalent volume is the absolute minimum size recommended for growing tomato plants. However, this small size is best suited to patios with little space or for growing dwarf cherry tomato varieties.
For most tomato varieties, larger containers in the 10 to 20-gallon range are ideal. This gives roots over 2 cubic feet of space to roam. Container gardening experts suggest the following minimum pot sizes
- Determinate/bush tomatoes: 10-gallon container
- Indeterminate/vining tomatoes: 15-gallon container
- Cherry tomatoes: 5-gallon container
Bigger is Often Better
The most prolific tomato plants are grown in larger containers whenever possible. While tomatoes can survive and produce fruit in 5-gallon buckets, they thrive when given more root room.
For determinate tomatoes a 15+ gallon container allows ample root space for bigger plants. Indeterminate varieties appreciate huge receptacles like 20-30 gallon plastic nursery pots or half whiskey barrels. The chart below outlines ideal container sizes
- Determinate/bush tomatoes: 15-gallon container
- Indeterminate/vining tomatoes: 20+ gallon container
- Cherry tomatoes: 10-gallon container
Other Factors that Influence Container Size
Along with variety, other factors determine the ideal pot size for patio tomatoes.
Planting time – Tomatoes transplanted earlier in the growing season have a longer period to grow larger before setting fruit. These plants appreciate extra root space.
Desired yield – Gardeners aiming for maximum tomato yields should opt for very large containers.
Available space – If container placement space is very limited, even large determinate varieties can fruit in a 10-gallon pot.
Watering frequency – In hot climates where tomatoes need daily watering, smaller containers dry out too quickly. Larger pots retain moisture better.
Soil quality – Rich, nutrient-dense potting mixes support vigorous growth in slightly smaller containers than regular potting soil.
Choose Wide Over Deep
For container tomatoes, the diameter of the pot matters more than depth. Tomatoes send roots out laterally more than down vertically. Look for wide containers versus narrow, deeper ones.
As examples, a 15-gallon nursery pot with a 24-inch diameter provides ample root room. For larger tomatoes, half whiskey barrels with a 24 to 30-inch diameter are excellent choices.
Use One Plant Per Pot
It can be tempting to plant 3 or 4 tomato plants together in an oversized container. However, for best results allow each tomato plant its own pot. This prevents plants from competing for water, nutrients, and root space. Yields per plant are always highest with one plant per container.
If space is very limited, you can plant compatible cherry tomato varieties together in larger containers. Determinate roma tomato types also tolerate sharing a pot fairly well.
Container Ideas for Tomatoes
Almost any food-grade container with drainage holes will work for patio tomatoes. Here are some excellent container options:
- Plastic nursery pots
- Wooden barrels or boxes
- 5+ gallon plastic buckets/pails
- Durable fabric grow bags or smart pots
- Concrete, ceramic, or terra cotta pots
- Stock tanks or galvanized metal tubs
You can also easily make DIY tomato planters from materials like wood, cinder blocks, or straw bales. Line permeable containers with plastic sheeting to hold soil.
Use Trellises and Cages in Larger Pots
Even with adequate root space, tomatoes grown in containers need extra support. Staking, cages, or trellises keep container plants upright, minimize disease, and improve yields.
Select a heavy cage or stake system proportionate to the pot size that can handle mature plant height and fruit weight. Place supports at time of transplanting to avoid root damage.
Providing an appropriately sized container establishes the foundation for growing thriving tomato plants on a patio or deck. For container gardening success, go as big as space allows when choosing pots for tomatoes. Filling larger containers with high quality potting mix will enable deep roots and bring bountiful tomato harvests!
Specific advice for tomatoes in containers
Use at least a 14″ pot, larger is better. Weve used up to 20″ pots and the plants responded by getting larger and producing more fruit. Bigger pots can hold more water and roots, which is very helpful when it’s hot outside and plants need a lot of water.
Use only compact, container varieties. There aren’t many of them yet, but more are being bred, and the 2010 program has a lot more varieties than the 2009 program did. See the variety list at the end for our comments and recommendations.
Use only potting media (soil) that is labeled for larger pots. Our trial mixes contained substantial composted pine bark blended with peat moss and perlite. Other mixes use coir, peanut shells and rice hulls for similar bulking purposes. Too much peat moss in the mix will cause it to compact too much during the growing season, which will lower the root mass. The plants won’t be able to grow properly and hold enough water for the day without this mass.
Container tomatoes benefit from upright support. Since plants grown in pots are usually shorter, a conical wire trellis with two rings has worked well. You can easily find these at garden centers. Installing these in the pot too late after planting will probably hurt the plants. Make sure to do it as soon as you plant the seeds. Some of the smaller cherry type tomatoes are so small that no support is required.
Tumbler Tomatoes: excellent saladette with good internal structure
Good tomatoes require a lot of nutrients. Most potting mix has fertilizer in it for about two weeks. After that, the plants need to be fed or their growth will slow down. Start by applying a timed-release, pelleted, fertilizer following the label directions for rate based on pot size. At about 2 weeks after planting, begin watering weekly with a soluble fertilizer. Until the plants begin flowering, you can use a balanced fertilizer with a 1-1-1 ratio such as 20-20-20. Once flowering, change over to a high potassium fertilizer. Most fertilizers blended for tomatoes fit this description. In our program, weve been using a fertilizer with a 9-15-30 plus micro-nutrients analysis. To get the same results, organic farmers can mix fish emulsion, green sand, kelp meal, and bone meal. Be sure to increase feeding as the plants grow larger. Apply more timed-release fertilizer after 10-12 weeks. There is good research to support the inclusion of seaweed-based supplements even with a strong conventional fertilizer program.
While insects are seldom a big problem on tomatoes, diseases are common due to our generally humid summers. Septoria leaf spot can happen to any tomato plant, and if you don’t treat it, the plants will lose their leaves just as the fruit is about to ripen. This disease is very easy to diagnose, it starts as scattered speckles or lesions on the lowest leaves. Then the speckles become larger and more numerous and spread upward eventually leaving dead leaves behind. Without those leaves, the plant cannot produce sugars and the other compounds that go into creating flavorful fruit. Eventually, Septoria leaf spot will kill the plant outright. From the first flower buds, apply either Chlorthalonil (Daconil and Fungonil in garden centers) or copper solutions weekly. If the weather is dry, you can reduce fungicide applications to every 2 weeks.
Note: In 2010 and 2011, we are testing different biological fungicides on tomato diseases. Based on the results of these tests, we hope to be able to add more biological options for controlling diseases effectively.
Harvest your tomatoes as they ripen completely. This timely harvest allows the plant to move resources to other fruit. Never leave rotten or overripe fruit on the plant as they will degrade other fruit. For the best flavored fruit, leave them on the vine until fully colored. At the first sign of frost, pick any fruit that looks even slightly ripe. Then, throw away the plant or cover it with row cover when it gets cool. The row cover will increase the heat and protect the plants from frost until it gets below 25F.
One truly excellent variety. We got enough from three plants to include this one in our tasting, and our panel really liked it. It had real tomato taste, good size for slicing and good yields. The plants are pretty small, but they need to be held up because the fruit gets heavy enough to break branches.
Good flavor in a saladette-sized fruit. Excellent yields for a compact plant and the fruit kept coming over a long period. Even though the fruit are small, this variety benefits from support.
Large quantities of paste-type tomatoes. Although not a lot of flavor, they were judged acceptable and fit a 14″ container. These did not require support.
Window Box Roma Fruit
Bushsteak’s fruit took a long time to get ripe, but when they did, they were big, meaty, and had a full tomato flavor. Even though there was a lot of fruit, it all ripened and was gone in two to three weeks. This variety may benefit from the use of row covers early in the season to promote faster growth. Must be supported.
Bushsteak tomatoes from a single days harvest in late august
The earliest yielding of the slicing container tomatoes in the trial. We started picking Super Bush right along with Bush Early Girl. Good flavor and good yields in a medium sized slicer. Must be supported.
Very small plants with minimal flavor. You can plant as many as 3 plants in a 14″ pot. No support required. We are going to add more potassium to this variety in 2010 to try to make it taste better.
Prepared by Steve Bogash, retired extension educator. The Penn State Extension, the Franklin County Master Gardeners, and the staff of the Penn State Southeast Research and Extension Center did a lot of work to grade these vegetables. Hillary Snavely, who was a summer horticulture intern in 2009, and Donna Berard, who is a Franklin County Master Gardener, did work that stands out.
- Vegetable and Small Fruit
- Beekeeping
- Green Industry
7 Best Tomatoes to Grow in Containers
FAQ
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