Every gardener has their own method of growing tomatoes. After a few seasons trialling various methods, I am sharing my tomato growing tips for a successful tomato harvest.
Every summer, I grow a variety of determinate and indeterminate tomatoes which include dwarf and micro tomatoes. I usually grow my indeterminate tomatoes in raised garden beds in the garden and dwarf tomatoes in raised planters about 70cm long x 37cm wide on a north-facing balcony.
Sow Tomato Seeds and Raise Seedlings
August is the time I usually start my tomato seeds in a greenhouse. For my temperate climate (Sydney), mid-August is usually the best time with daytime temperature starting to warm up. Here is the method I follow.
Sow 3 seeds 5 mm deep in a 5 cm round pot filled with quality potting mix that has the Australian standard red tick then top it with a thin layer of seed raising mix and a layer of vermiculite on top. This method reduces the need to prick seedlings from a tiny cell, transplant them and pot them up while they’re tiny and delicate. Furthermore, there is no need to add nutrients at this stage. The thin layer of seed raising mix aids in germination while the vermiculite helps to retain moisture.
Before germination takes place, water the surface with a fine mist or gentle spray using a water bottle. Once the first leaves appear, switch to watering from the bottom. This is as simple as adding 2-3cm of water to a container and leaving the pots to soak for about 10 minutes.
Once seedlings have reached 5 to 7 cm in height, carefully divide the plants, keeping the strongest in the pot and repotting the others as back up.
Tomato Growing Tips: Soil Prep for Successful Tomato Harvest
A couple of weeks or so ahead of transplanting seedlings, start by prepping the soil where the tomatoes will be growing over the spring and summer periods.
Soil prep is a crucial step for successful growth. Start by removing spent plants, old roots and aerating the soil with a garden fork. Amend the soil using a combination of mushroom compost, blood and bone, worm castings, potash, poultry manure and top up with premium potting mix.
Transplant Seedlings into their Final Position
Once the seedlings have reached 10 cm in height or more for indeterminate tomatoes (less for dwarf varieties), begin transplanting them into their final position. Make a hole slightly larger than the size of the pot, gently remove the lower leaves and plant up to the first set of true leaves. Stake indeterminate tomatoes at the time of planting to prevent root disturbance later. Some dwarf tomatoes also benefit from staking so if you’ve grown the variety before and you need it needs a helping hand, stake it while transplanting. Water in with a seaweed tonic, add sugar cane mulch and lightly water in again to keep the mulch in place.
TIP: It is best to transplant seedlings in the late afternoon to give them a better chance to settle in their new, permanent location overnight when the temperature is cooler.
Tomato Growing Tips: Plant Maintenance
Tomato plant maintenance requires commitment and dedication. Here are my top tips:
- Water consistently and deeply to prevent the fruit from splitting and to minimise the chance of blossom end rot.
- Water early in the morning and avoid overhead watering to minimise the chance of diseases.
- Train the stem up to two leaders and remove lateral branches.
- Check for pests daily and look under the leaves, fruit and near the soil.
- Prune suckers by gently twisting them off the plant. Tomato suckers are side shoots that grow at 45 degree angle between the stem and leaf.
- During the early stages of growth, apply a seaweed tonic fortnightly.
- Bag the fruit using organza bags as soon as it forms. Ensure it is put on tight to prevent any caterpillars from entering.
- If you have a problem with rodents or birds eating the fruit, gently wrap plastic disposable oyster packaging you get from the supermarket. You can find detailed information in a previous article.
- Midway through the season, apply a little potash to the soil and water it in well.
Tomatoes are best left to ripen on the vine but there are many reasons why you may need to harvest beforehand. It could be the end of the season and you need the spot, disease may have set in or you may have hungry caterpillars destroying the fruit. This begs the question, can you harvest green tomatoes?
When tomatoes start to develop a blush, you can harvest them and let them ripen on a window sill or kitchen bench. You can also ripen them in brown paper bags with a banana. Never store tomatoes in the fridge if you want them to ripen. They need warmth or they will remain green. If harvest green tomatoes that don’t have any signs of blush (with the exception of the green tomato varieties) chances are they will rot before they ripen.
Tomato Growing Tips: Seed Saving
Saving seed from fruit you’ve grown not only saves a few dollars but you get plants that have adapted to your very own microclimate. Choose your best tomatoes for seed saving, and do so when the plant is thriving and not at the end of the growing season. Saving tomato seeds can be as simple as laying them on a paper towel or fermenting the seeds in water. You can read about the three methods of saving tomato seeds in a previous article.
Here’s to a bountiful tomato harvest!