Here's a collection of tomato growing tips to help you grow successful tomatoes this season.
Planning & Seeding
- If you’re planning to grow in containers look for a determinate or semi-determinate variety as it will have a more concentrated fruit set and compact habit (whereas indeterminate varieties will easily grow vines 10’ long). Cherry or midsize tomatoes also can produce sooner than large beefsteaks which also may be an important factor to where you’re growing
- Plan where you’ll put your plants. Plan to grow in a spot that receives at least 6 hours of sunlight. If late summer rain and blight tend to be an issue in your area, greenhouse/overhangs may help ensure success as well as provide protection from wind. If you’re growing in a container, make sure they are big enough (3-5 gallons) and have good drainage and consider having or being able to move your pot against a sunny wall under the eaves of your house.
- Start seeds 6-8 weeks before planting date in your area, too early and plants can become leggy and/or root bound. For the Lower Mainland and Vancouver Island this can be mid-late February right up until mid April.
- Seed tomato seeds directly into a potting mix (such as Sunshine #4), covering seeds ¼” deep. Optimal soil temperature for germination is 75-85°F with seeds germinating in 4-14 days.
- Keep seedlings under very bright light (natural or grow lights) helps prevent legginess. Using a domed clear lid on a seeded tray helps keep soil moist when germinating.
- Transplant into 4” pots with a rich potting mix when they have their true leaves ~10 to 20 days. Use a mix of ½ potting soil, ½ compost plus 1 tablespoon per pot soil amendment. For a soil amendment it helps to know about your soil pH. If your soil is correctly balanced or high in nitrogen, use a fertilizer slightly lower in nitrogen and higher in phosphorus, if you’re slightly lacking in trogen go with a balanced fertilizer. When in doubt ask staff at your farm supply or garden centre.
- When your starts are looking robust in their 4” pots, you can transplant hardened seedlings into a greenhouse or a field when the risk of frost is low. Soil should be 50-55°F
- When transplanting our make sure your starts are well watered the morning before, dig a good 10” deep hole (if the plants are tall, you can plan to set them as deep as the second set of true leaves). Add a compost and soil amendment (~½ cup depending on product).
- Turn the pot upside down supporting the plant and tap the bottom of the pot, the plant should come out easily. Press the soil firmly around the plant to form a slight depression to hold the water. Water the plants in so the soil will settle around the roots of the plant, be sure to water the soil, not on the plant. Protect the plants with floating row cover or plastic covers while the evenings are still cool. Set the plants slightly deeper in the soil outdoors than they were growing in the container. If the plants are tall, you can set them as deep as the second set of true leaves.
- Distance between plants will depend on the variety and also your growing method, in general to accommodate trellising plants at 18-24” apart in rows 3’ apart. If using cages, give a bit more room (24-36” at rows 4’ apart).
TrellisingDetermine how you will support or trellis the plants at the time of planting (your future self will thank you!) Options can include using any of the following depending on what is best suitable for the scale and size of your growing space.
- Wooden stakes (~8’ long x 1.5” thick) inserted ~4” from the plant and about 1.5-2’ deep. Plan to latch the plant to stake via commercial tomato clip or tape product, or strips of soft cloth/nylons. Tie under leaflet branches every ~12 inches
- Tomato cages or spirals (best for smaller varieties) placing around the plant while they are still small. Plants may need to be tied in order to grow up the center of the cage.
- Overhead string - ideal for high tunnel/greenhouse production, using the cross beam of a rafter or support to hang down 1-2 strings per plant on which it can be guided around to climb (can also be used for small outdoor productions using a free standing structure such as this video demonstrates)Ensure the string reaches to the ground and securely tie to the base of the plant without knotting or damaging the stem. As the plants grow, wrap the vine around the string a little bit at a time or, alternatively, secure the plant using commercial clips or twine attaching below a major branch
- “Florida weave” aka "basket weave" - works best for tomatoes grown in the field in long single rows. Basic premise is driving long stakes/T posts 1’ deep into the soil, in the middle of the row every 2-5 plants. Using lightweight twine, the first line is affixed to an end post 8” from the ground then runs down the front side of the first set of tomato plants, on the back side of the next post, and then returns to the front. Make a full loop around at least every other post so the line doesn’t slip. At the end, tie off and work back down the row, mirroring the first line (second line runs behind all plants and in front of posts). As the plants grow, repeat this process, setting another line every 8”inches. Ensure your end stakes are well anchored as they will bear the weight of the plants as they grow. Take a look at videos online to see this technique in action.
- Watering - In general tomatoes need 1-2” of water per week but will vary with temperature, soil type etc. Heavy weekly soakings are better than frequent light soakings that tend to maintain shallow root systems. Keep moisture off the plants, watering right at the soil or using drip tape works best, avoid splashing the leaves. Restricting watering late July/August can encourage the fruit to ripen.
- Pruning - For indeterminate plants, remove any suckers (stems growing from where the leaflet branch joins the mainstem or in the “armpit”) to keep the foliage under control, which will help set a crop of larger fruit. Be careful to remove the suckers and not the fruiting stems or leaflet branch. Do not remove suckers from cultivars with a strongly determinate growth pattern.
- Pollination - tomatoes do not rely on insects for pollination but those under cover can be encouraged to pollinate and set fruit but having the stems tapped so that the plant shakes pollen loose within the self pollinating flowers. If you’re pruning and staking weekly you are likely jostling the plants enough to do this!
- Common pests & Diseases - these can include light and early blight, Bacterial Canker, Blossom End Rot (caused by a calcium deficiency). There are lots of resources out there on these common diseases and prevention is always the best strategy. Staking, stringing or pruning the plants are all best done when the plants are completely dry, this will help avoid the spread of any bacterial and fungal diseases. Remove any weak or unhealthy leaves, use clean tools between plants and again strive not to get water on the leaves.
- Harvesting - harvest tomatoes fully ripe for best flavor, this can vary depending on the variety! After harvesting, store between 55°- 70°F at 95% relative humidity. Storing below 50°F can result in chilling damage.
Excited to get started with your tomatoes? Shop the tomato collection here.