Container-grown food can be very tasty. It needn’t matter whether you’re using heritage or modern varieties: the secret is good fruit-ripening sunlight for releasing sugars, good compost and regular feeding to top up compost nutrients.

And freshly picked home-grown is usually tastier than shop-bought because fruit and veg flavour weakens after picking.

We can’t do anything about the sun, which may explain why some tomatoes from warmer climes than Scotland are sometimes very tasty. But we do control how our plants are grown.

Fruit from plants grown in the open ground often taste best because the tomatoes, strawberries, raspberries or cucumbers extract nutrients with the help of soil organisms.

So if plants are to do as well in pots, they need a good, steady feeding regime.

I know I keep banging on about the virtues of home compost, but it is crammed with living soil organisms and micronutrients.

And, since commercial compost is sterile it is never as good, even when its chemicals are well-balanced.

Over the years, I regularly compare both materials and always enjoy a larger crop of tastier tomatoes from home-made compost.

But whatever kind of compost you use, you have to keep it in good heart by feeding plants regularly. Weekly when the plants are flowering and twice weekly when the fruits are developing.

At this flowering and fruiting stage, plants need the larger potassium intake they’ll get from liquid tomato feeds like Tomorite.

An excellent free alternative is liquid from comfrey plants grown in the garden. I look to produce 40-50 litres of the stuff every year, extracting juice exclusively from the leaves.

I place a weighted bucket on top of the leaves in the barrel, with a washing up bowl beneath the barrel to collect the liquid from holes drilled in the bottom of the barrel.

I wouldn’t consider soaking the leaves in a barrel of water as is often wrongly recommended. Believe me, this method releases a revolting stink, so if you respect your nose, you’ll follow my method and add more water to a richer brew after fermentation.

This feed can be used for other container-grown veg like peppers and cucumbers as well as ornamentals. With edibles, start feeding weekly, following manufacturer’s recommended doses. With liquid comfrey I use 100ml per 5 litres of water.

For best results the feed must stay in the pot and not be washed though too quickly.

This starts happening when the compost begins to lose structure after 2 - 3 months.

The surface dries out and shrinks, exposing more of the root collar.

Help to prevent nutrient loss by applying a top dressing like wormcast, leafmould or a layer of commercial compost.

You could even use last year’s compost to simply act as a mulch. When applying the feed, first water the pot as usual to get the soil moist and receptive, following this with the liquid feed.

Plant of the week

Salvia elegans, Pineapple sage, is a tender shrub with soft, aromatic foliage that begs to be stroked. In summer it bears a long succession of brilliant red flowers on tall spikes. It needs sun and shelter so is best grown in a really large pot and overwintered in a frost free shed or greenhouse. Older plants start flowering earlier but all will put on a spectacular show until the autumn weather gets really chilly.

Follow Dave on Twitter @boddave

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