GARDENING

Up the yield and extend the harvest with a little summertime TLC

YOU might have all the herbs you need right now but if you want a steady stream well into autumn then you need to act now. Re-sow some annuals (such as rocket), cut back perennials (chives, for example) and tidy up the likes of thyme and mint.

Chervil, dill, salad rocket and coriander are quick growing herbs and spring sowings will be running to seed by now. For a continuous supply of tasty leaves you need to sow them at least twice.

The soil is warm now so direct sowing into open ground should be easy, provided you’re not plagued by rodents and molluscs. If you are hampered by these slithering, nibbling herbivores, protect the seedlings with yogurt pots.

However you sow herbs, regular – possibly daily – watering is critical. Small seed, especially salad rocket, is prone to drying out. After germinating, it quickly perishes beneath a strong midsummer sun unless the ground is kept constantly moist.

I also like to grow some herbs in pots to protect them from predators. And with coriander, I’ll even make four successive sowings in the same pot. Here’s how.

I start in spring with a few seeds in a 10-litre pot in the greenhouse. Once the risk of frost is past, I put the pot outside in a sheltered place. At that stage, I poke a few more seeds into spaces between the small plants. When the first sowing starts going to seed, and the second is fully established, I poke in a few more seeds. By mid-July, the second sowing has been used – leaves, stems and even roots – so there’s room for a final sowing. This intensive cropping requires a lot of feed and watering. I find a top dressing of wormcast at each sowing does the job, but leafmould plus a liquid feed would also work well.

Like annual herbs, some perennials are past their best now. As they start putting their energies into setting seed, the whole plant becomes coarse and dry. So, for an extra flush of chives, cut back to about 2cm above ground level and water thoroughly.

Sorrel is equally disappointing when it starts sprouting a seed head. The first big tangy leaves are replaced by lots of narrow, coarse ones clinging to a tough flowering stem. Cut these flowering stems down to ground level to encourage regrowth.

But don’t run amok with your shears to leave yourself sans herbs. If you have two or three clumps of chives, stagger the clipping, so you’ll have a supply while the early ones regrow. You may find, as I do, that clumps reach maturity at different times, so it’s easy to choose the first for chopping.

In contrast, the whole mint bed reaches the flowering stage at the same time. But if you want an ongoing supply, cut the crop back in stages. This approach also applies if you’ve only one clump of mint or chives: cut it back in sections.

Sadly, this tactic doesn’t work with salad burnet. After a few heavy showers the whole plant becomes a mess, with a ring of tangled stems collapsing over neighbours and leaving a bare centre. The only answer is to cut the whole lot to two centimetres above the ground and wait for regrowth.

Thyme, lavender and sage won’t regrow this way. As Mediterranean plants, they start growing much earlier in the year and become dormant during the hot, dry summer. So limit the tidy up to removing spent flower heads. Use hand shears for thyme. With lavender, hold the flower spikes in one hand and, with the other, use secateurs to remove them. Sage flower stalks should also be snipped back individually. Simply remove faded flower stems, but don’t cut into the old wood.

Chives are annuals and will be focused on setting seed now, so trim them back to trigger new growth