Growing a healthy crop of tomatoes this summer

I recently visited my local garden centre and couldn’t help overhearing how many customers had questions about growing this wonderful summer fruit. Let’s take a look at how to grow healthy, juicy, and delicious tomatoes, and keep them producing all summer long.

Types of tomatoes
There are two types of tomatoes — plants that grow in a bush and plants that cascade (which need staking). The bush varieties are self-supporting (no staking needed), produce early in the growing season and tend to produce a lot of fruit at once. The staking varieties produce more consistently and have a longer growing season.

Pests and diseases
To prevent pest and disease attacking your tomatoes, a key action to take is to create airflow around the base and throughout the plant. This lets the wind through and can keep your plant free of pests and disease.

To thin the leaves, remove the first 30cm of lateral stems and leaves from the ground by snapping them off at the main stalk. Try to do this on a windy day to enable the “wounds” to heal and prevent them being infected by disease.

Remove unwanted lateral stems regularly, unless you are using these to espalier (attach) your plant along a trellis, where one tomato plant can produce along a two-metre span.

Tomatoes are hungry plants and need regular feeding on a weekly or fortnightly basis. However, they don’t like too much nitrogen, which encourages excessive leaf growth. They prefer phosphorous and potassium in higher quantities, which can be found in a kelp and organic fish emulsion fertiliser. These nutrients will improve the fruit crop and aid in preventing blossom end rot.

If you have a fireplace, a side dressing of potash (wood ash contains potash) throughout the growing season will give you a natural supply of potassium; apply at the base of the plant and water in well. Chopped up banana peels around the base are also a great source of phosphorous. Liquid feeding your plants over the summer months is preferable as the plant can absorb this more effectively than a solid fertiliser.

Tomatoes also love a feed of themselves! When removing leaves from the plant, soak in a bucket of water overnight, or for up to two days, then pour it back on around the base. You can also add kelp and fish fertiliser to this mixture.

Watering your tomatoes on a regular basis is essential for even and productive growth. Watering three times a week is enough; this encourages their roots to go deep into the soil where it is cool. If you’re growing tomatoes in pots, fill the base tray with water so the plant can pull it up from the bottom.

Always water the base of the plant and not the leaves as this can cause pests and disease,
and wastes water as there is less absorption. And to help prevent pests and disease, always water in the cool of the day, preferably in the morning.

Top tip
Remove yellow and diseased leaves from your tomato plants and dispose of them separately from your compost to prevent the disease cycle repeating itself. Happy gardening!

Look out for my monthly column in the New Zealand Herald’s Monday food and wellbeing magazine BeWell and on

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