How to Revive Tired Tomato Plants in Late Summer – 5 Tasks to Keep the Harvests Coming

Tomato plants can look a tad weary in late summer. The stresses of quickly growing stems and leaves, developing and ripening fruit, and facing hot midsummer temperatures can take their toll on plants. There is still time left in the season, though, and you can encourage them to end on a high.

Growing tomatoes in late summer is more about gentle encouragement and preserving what you have got. You need to ensure the fruits you have develop healthily and ripen, and that is the priority rather than encouraging huge flushes of new growth.

So, what can you do to rejuvenate ageing and tired tomato plants in late summer? The answer is selective pruning, regular watering and feeding (you can get Miracle-Gro water-soluble tomato food at Walmart), harvesting fruits when they are ready, and controlling any problems. Here’s what I do with my tomatoes to revive and prolong plants through the final stages of the season.

Prune Leaves and Shoots

As the season goes on, tomato foliage can look a little worse for wear. Tomato leaves can turn yellow, brown, spotted, or deformed. Many factors can cause tomato leaves to curl or turn discolored, including nutrient deficiencies, poor watering, diseases, and natural old age.

For healthy plants, it is beneficial to remove any less-than-desirable foliage towards the bottom of the plant. If you haven’t been pruning tomatoes and removing lower leaves through the season so far, do it now.

It keeps plants healthy by improving airflow, allows more light to reach fruits to ripen them, and makes watering tomato plants easier – it is plain sailing to direct water to the base of the plant without unnecessary foliage in the way.

As we get towards the end of the season, you also need to continue removing side shoots as they appear. You need to put as much energy as possible into ripening existing fruit, rather than new stems.

A pair of sharp pruning shears is crucial for removing tomato leaves and larger side shoots. I have often used a pair of Japanese pruning shears like these Okatsune pruners on Amazon for this task and found them sharp, lightweight, and comfortable to use.

Routinely Feed Plants

Hopefully, you have been fertilizing tomatoes every week or two since they started flowering, which is the trigger point to start giving them a tomato feed (or any fertilizer lower in nitrogen and higher in phosphorus and potassium) that encourages fruit development.

If you have, that is good, and you should continue this until around three weeks before your first frosts, or when your last ripe tomatoes are ready to harvest. Feed plants every two weeks, or every week if you are growing tomatoes in pots or grow bags.

However, if you haven’t been feeding your crop regularly, now is the time to make a positive change. They may desperately need a pick-me-up, and a lack of essential nutrients could well be why your plants look tired or are not producing a good crop so far.

Don’t give tomatoes too much nitrogen now, as it’ll encourage foliage growth. You want to encourage fruits to develop and ripen. Use a liquid tomato fertilizer – such as this tomato booster at Walmart – and feed plants weekly to breathe some new life into them.

Alternatively, you can feed tomatoes using a seaweed fertilizer, such as this fish and seaweed liquid fertilizer on Amazon, or make your own tomato fertilizer by brewing a nettle or comfrey tea.

Water Consistently

Tomatoes are very susceptible to changes in moisture. How and where you grow the crop can make a massive difference, and will impact how much you need to water your tomatoes to keep them thriving.

For example, tomatoes growing in a greenhouse are likely to experience sweltering temperatures in midsummer. If they are in grow bags – or indeed even if you use grow bags to grow tomatoes on a balcony or patio – the soil can dry out incredibly quickly. I have seen tomatoes go from happy to wilting in a blink of an eye during a heatwave when they are in pots or grow bags.

When tomatoes go short on water, plants wilt, drop flowers, and curl leaves as they try to conserve moisture. The fruit is also affected; inconsistent watering – periods of drying out followed by a soaking – commonly causes tomatoes to split or succumb to blossom-end rot.

Tired tomato plants could easily be suffering from drought stress during late summer. The key is to water consistently and, when you do water plants, water deeply. If you allow the soil to go back and forth between dry and waterlogged, you’ll have miserable tomato plants that likely won’t provide much towards the end of the season.

Pick Tomatoes When Ripe

Harvesting tomatoes is super-satisfying – a summer highlight. A perfectly ripe tomato will be deep red (or yellow, orange or purple, depending on the tomato variety) and not green, feel firm but give a little when squeezed, and come away from the plant easily when twisted.

You need to keep on top of picking tomatoes; otherwise, it slows down the ripening of newer ones. The plants will focus energy on the older fruits, which may crack, go moldy, or simply drop off if they are left too long. This halts the production of new blooms and fruits, and other tomatoes still ripening on the plant may go without nutrients.

To keep your harvests going into late summer and fall, it is crucial to check your plants regularly and pick the fruits once they’re ready. To help tomatoes ripen on the vine later in the season, remove foliage, snip off new flowers, and cut the top of the central stem to focus the energy into ripening the existing fruits.

Watch for Pests and Disease

Late summer is unfortunately a prime time for plants to show the effects of pests and tomato diseases. It can cause them to look tired and show symptoms such as yellowing foliage, stunted growth, a white coating on leaves, or wilting.

Common tomato pests like aphids, whiteflies, and spider mites can cause issues. But it is the tomato hornworm that causes most damage, as the caterpillars can completely defoliate plants. The best way to combat tomato hornworms is to hand-pick the caterpillars or spray plants with Bacillus thuringiensis, available at Amazon.

Young caterpillars can be targeted with insecticidal soap (available at Walmart), which is also a proven way to get rid of aphids and other small soft-bodied pests, such as flies and mites.

If you do see any signs of disease, fast action is crucial to preserve your plants and any future harvests.

Thankfully, diseases such as blight, leaf spot, and powdery mildew can be combatted by pruning off diseased leaves and watering the soil rather than the foliage. You can also spray copper fungicide like this from Amazon.

However, bacterial diseases such as wilt cannot be cured, and plants must be removed and destroyed.

What to Shop

Around 4-6 weeks before the end of the season, it is advisable to cut the growing tip of the tomato plants.

This technique, known as topping, encourages the plants to focus their energy on ripening all existing fruits rather than producing new flowers and fruits. This is a crucial, and often overlooked, task to ensure you get the most from your plants before their time is up. It is a tomato growing mistake not to top plants, and you’ll miss out on harvests as a result.

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