There’s a risk that warm-season staples like tomatoes and beans simply begin to fizzle out in late summer. To keep them going, we need to manage plant health and extend the conditions they need to thrive. Here are my six strategies to make it happen...
1. Keep Picking
Don’t let plants like beans and tomatoes set mature seeds. The moment the plant thinks it has ‘done its job’ by ripening seeds for the next generation, it slows down production. But keeping crops coming is simple.
For tomatoes, pick fruits as soon as they’re ripe. Beans need a keen eye – check plants at least every couple of days to pick pods promptly, because even slightly swollen pods can trigger a slowdown.
And then there’s our ever-dependable summer staple, courgettes. Production may be starting to slow towards the end of summer, but we can keep them pumping out fruits for longer by harvesting them while they’re still quite small. Larger fruits signal the plant to stop producing. Courgettes taste really dense and nutty when they're still quite small – much better than a big, watery old marrow – so that’s even more reason to pick them often!
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A tomato fertiliser can give podding and fruiting crops the nutrients they need to keep producing for longer
2. Feed and Water
You’ve been feeding and watering consistently throughout the summer, but it’s never been as crucial as right now.
Feeding gives plants the energy they need to keep on producing well into autumn. Give tomatoes a high-potassium tomato feed every seven to ten days, whether using an off-the-shelf tomato feed or something special like a homemade fish fertiliser.
Beans may benefit from the occasional balanced feed. Avoid using fertilisers containing too much nitrogen (the ‘N’ in the N:P:K ratio on the packet) this late in the season, otherwise you may get more foliage than pods. A standard tomato feed is just the ticket. Courgettes, too, will benefit from a weekly liquid feed to replace nutrients after fruiting heavily earlier in the summer.
When watering, avoid swings between dry and wet soil as they can cause blossom end rot in tomatoes and tough bean pods. Aim to keep the soil consistently moist.
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Tip-pruning tomatoes redirects their energy into ripening existing fruits
3. Tidy and Prune
Plants can look a bit tattered and tired by late summer, but by managing foliage with a little tidying and pruning we can give our summer staples a new lease of life.
Cut off and compost any yellowing or diseased tomato leaves, and keep removing sideshoots from vining (cordon) varieties. When there’s likely to be only a few weeks left in the growing season, consider ‘stopping’ plants by pinching out the main growing tip. This will focus the plants’ energy on ripening existing fruits rather than forming new fruits that may not ripen in time before the end of the season.
Remove any dead leaves or stems from beans to help improve air circulation and, with it, general plant health. Cut away older, sprawling leaves from summer squash and courgettes to enhance airflow and open up plants to light. Mildewed leaves are inevitable, at least in my garden, but these too can be removed to encourage fresh, new leaves, and to improve that all-important airflow.
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Damping down hard surfaces in greenhouses can help keep spider mites at bay
4. Stay Vigilant
Late-season challenges are aplenty, but that doesn’t mean we should throw in the towel! Remove any plant debris, avoid splashing leaves when watering, and ensure good airflow to help to slow the progress of diseases.
Keep an eye out for spider mites and aphids as the weather changes. Both can flare up in warm, dry, late-summer conditions. Wetting hard surfaces in greenhouses or polytunnels can help to keep the humidity high enough to put off spider mites.
As nights start to cool off, use cloches, horticultural fleece or clear plastic-covered tunnels to trap heat around warm-season crops and keep those harvests coming for longer. Container-grown crops can be moved to sit against sunny walls which will radiate warmth at night to keep them cosy.
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Enrich soil to give plants the strength they need to keep on going
5. Give Plants a Boost
As well as the occasional liquid feed, beans and squash family plants may also benefit from a light top-dressing of compost or well-rotted manure, which can sometimes be enough to give plants a second wind.
Tomatoes respond to a light prune plus a last push of feed to help them channel energy into ripening.
For those gardening in warmer climates there may still be time to sow one last batch of dwarf beans, or perhaps a final fling of fast-maturing cucumbers, to keep the harvest going after the first wave of plants tires out.
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When the weather turns cold, harvest all remaining green tomatoes and bring them indoors to ripen
6. Ripen Green Tomatoes
There are a couple of things we can do to coax along stubbornly green tomatoes and ensure a final picking of this most treasured fruit.
As summer tips into autumn, some gardeners like to prune away any masses of dense foliage to expose fruits to full sun. There are two schools of thought about this: some believe that the energy to ripen fruits comes from the plant, so leaves should be left in place, while others think that direct sunshine has an effect. My compromise is to just remove a few leaves that are heavily shading fruits.
If frosts threaten, bring any still-green fruits indoors to ripen in the warm. You can speed them along still quicker by popping them into a paper bag with a ripe banana.
