Heirloom tomatoes are prized for their incredible flavors, colors, and unique traits passed down through generations. While often grown in gardens, heirlooms can thrive in containers too with the right care. Follow this step-by-step guide for tips on choosing varieties, pots, soil, placement, watering, fertilizing, and more to grow robust heirloom tomatoes on your patio or balcony.
Selecting Heirloom Varieties for Containers
When choosing heirloom tomato varieties for pots opt for compact container-friendly types
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Determinate/bush heirlooms These grow to a short, bushy shape instead of vining making them ideal for containers. Good options include Roma Ace 55, Bison, Moskvich.
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Dwarf/micro-dwarf heirlooms: These produce full-sized fruit on pint-sized plants under 3 feet tall, perfect for small pots. Try Red Fig, Principe Borghese, Tommy Toe.
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Small-fruited heirlooms: Cherry-sized fruits on manageable vines work well. Consider Black Cherry, Sungold, Sweet Pea, Yellow Pear.
Choosing the Right Pot
For robust heirloom tomato plants, use the largest container possible:
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10+ gallon pots or half wine barrels allow for ample root growth.
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Dwarf varieties can work in 5 gallon buckets. Micro-dwarfs grow in small 4-6 inch pots.
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Use containers with drainage holes to prevent soggy soil. Add a tray underneath to catch excess water.
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Fabric grow bags, wood barrels, plastic nursery pots all work if properly drained.
Preparing Potting Mix
Heirlooms need nutrient-rich, well-draining potting soil:
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Use a quality potting mix with added organic compost or manure.
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You can create your own mix blending potting soil, compost, perlite or vermiculite for drainage.
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Soil should have a pH between 6.0-6.8. Test strips can confirm proper acidity.
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Fill pots 2/3 full leaving room at top for watering.
Sowing Seeds for Transplants
Start heirloom tomato seeds indoors 6-8 weeks before last spring frost:
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Sow seeds 1/4 inch deep in seed starting mix in trays or pots. Keep soil moist.
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Place containers on a heat mat or warm spot for ideal 65-85°F soil temperature to aid germination.
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Once sprouted, move to a sunny spot. Grow seedlings to 6 inches before hardening off.
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Harden off plants by gradually exposing them to more sun and time outdoors over 7-10 days before transplanting.
Transplanting Tomato Plants into Containers
Transplant hardened off heirloom seedlings into prepared pots:
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Bury some lower leaves and stem underground for more root growth when repotting.
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Water in transplants deeply without wetting leaves. Provide shade for a few days while establishing.
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Add support right away, staking indeterminate types and caging bushier determinate heirlooms.
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Place 1 plant per 10+ gallon pot. For dwarfs, plant 1 per 5 gallon container. Micro-dwarfs need just 4-6 inch pots.
Caring for Container Heirlooms
Heirloom tomatoes thrive with consistent, attentive care:
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Check soil moisture daily, watering when top inch is dry. Avoid wetting foliage.
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Add mulch like straw to retain moisture and discourage weeds.
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Feed every 2-3 weeks with organic tomato fertilizer once flowering begins.
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Prune indeterminate varieties by pinching off suckers for controlled growth.
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Monitor for common pests like hornworms, aphids, whiteflies and target early.
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Stake, cage, or trellis plants to keep fruits off the ground and prevent disease.
Ideal Placement for Pots
Proper positioning ensures happy container heirlooms:
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Tomato plants need 8+ hours of direct sunlight for ample fruit production.
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Morning sun is ideal in hot climates to limit afternoon heat stress. Provide shade if temps exceed 85°F.
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Elevate pots on tables or blocks to prevent disease. Add casters to movable pots.
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Group together for efficient watering and care. Just space appropriately for air circulation.
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Move portable pots to protected areas or indoors if strong winds or frost is expected.
Harvesting Homegrown Heirlooms
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Begin checking for ripe tomatoes 2-3 months after transplanting when fruits start reddening.
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Harvest heirlooms when fully colored but still firm. Slight softness indicates peak flavor.
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Twist or clip off fruits, leaving stems attached if possible to avoid opening wounds.
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Enjoy fresh sliced tomatoes immediately for best taste. Refrigeration dulls flavors.
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Let any unripened green tomatoes mature indoors if winter frost threatens.
With proper variety selection for container growing and attentive care, you can grow bountiful crops of incredible heirloom tomatoes on your patio or balcony for seasons of fresh, homegrown flavor.
Can you grow tomatoes in your zone?
When it’s warm outside, tomatoes do best. You can grow tomatoes in zones 3–10 as long as the temperature doesn’t drop below 55 ℉. For best growth, keep the temperature between 70 and 85 ℉. If it gets too hot, cover them with shade cloth or move them to a cooler spot.
Being in zone 10, I like to start them inside in early spring and let them go outside when it gets to 55 ℉ at night (or warmer). This ensures that I can have a long season. I’ve put tomatoes away over the winter before and had them come back to life in the spring and produce a lot of fruit.
How to plant tomatoes from seeds
1. Choose a tomato variety. You really have an abundance of tomatoes to choose from. Some of my favorite varieties are celebrity, brandywines, and cherry tomatoes. I like buying seeds from San Diego Seed Company and Kitazawa Seed Company. They say that buying seeds from a local seed company is best because you know these seeds work well in your region.
2. Choose a seed starting tray. When I start my seedlings, I like using reusable seedling trays such as Epic Gardening’s 6-cell trays because they’re durable and I can reuse them in the future. I would not recommend using compostable peat moss trays because they dry out quickly and don’t compost quickly enough once you transplant the seedlings. This has caused some plants to not grow as substantially because they become root-bound.
3. Moisten your soil, then add soil to the trays. You can keep the soil from moving around or getting too tight when you water the tops after planting the seeds. I’ve totally forgotten to pre-wet the soil before and ended up with concave cells in my trays. When you put the soil in the trays, don’t pack it down too much—you want the soil to drain well, so just lightly pat the soil into the trays.
4. Make holes in the soil, drop seeds in. Check the seed packet to see how deep to plant the seeds, then make a hole in each seed cell that is that deep. Plant two to three tomato seeds about ¼ inch deep, and then pat the soil over the holes without pressing it down too much.
5. Keep the soil between 55-70 ℉ for proper germination. I use heating pads that gently warm the seedlings at a constant heat to properly germinate them.
I use Vivosun heating pads to raise the temperature of the seedlings to 10 degrees above room temperature. I also put a lid on top of the seedling trays to keep the humidity and temperature stable. Also, I use a shop light with at least 3000 lumens so that the seedlings have light after they sprout. To learn more about starting seeds indoors, you can read a quick guide here.
How Do I Grow Heirloom Tomatoes in Containers? : Gardening Tips
FAQ
Do heirloom tomatoes need a trellis?
Are heirloom tomatoes difficult to grow?