Growing vegetables under cloches

We don’t use cloches much at the allotment, for two reasons:

1. We start almost everything off in the greenhouse, and only move it outside when the weather is clement
2. We have a nine raised beds – six of them for rotated crops (the others hold early strawberries, late strawberries and asparagus) so we can cover them with fleece if we want to start crops off under cover.

However, we are wondering about whether to put cloches over our earliest potatoes – my parents, down in Torquay have already got their first earlies in the ground under cover, and they were harvesting a month before we were.

At this time of year, lots of gardeners are covering their soil with cloches to warm it up – I’ve never been entirely convinced by this process for two reasons – first I don’t quite see how the soil is warmed (okay, covering it can remove the chill of frost but it can’t actually make it any warmer than the ambient air temperature unless you use black plastic to conduct heat) by covering it, and second, covering soil ignores the action of convection: soil isn’t just made warmer or colder by the sun or frost but also by the movement of water through the soil which freeze in cold temperature and then melts in warmer ones. So if all the soil around the cloche freezes, then surely when it melts again, the meltwater will penetrate quite a way into the soil that hasn’t frozen at all, and drop its temperature?

On the other hand, the value of cloches in protecting tender plants, whether those overwintering or new seedlings, is undoubted – and that’s where we cover our raised beds with one of three media: glass, horticultural fleece or mesh, depending on the plants in question.

I now have ten beef tomato seedlings, so I shall be offering at least seven of them at seedling swaps, and I’ve just covered one of our empty raised beds with fleece and sown the first row of salad seedlings.

Labels: allotment-cloches, allotment-vegetables

Companion planting

I’m in two minds about this. I do undertake some companion planting: mainly things I remember my granddad doing such as plant French marigolds between tomato plants to deter aphids, growing carrots and leeks together (I think the leeks smell strongly enough to confuse carrot fly, although it could just be that he liked the look of carrots and leeks together, isn’t it odd how we pick up habits without really thinking about them?) and using nasturtiums as a sacrifice crop for cabbages – because the caterpillars eat the nasturtiums and leave the cabbages alone.

But can it really be true that those same marigolds can smother bindweed? I don’t think so. Not on any allotment I’ve come across, anyway. And does celery really deter cabbage white caterpillars from brassicas – I’d love to believe so, but I don’t think I’ve come across anything, except horticultural mesh, that really keeps the caterpillars off. Or rather, keeps the butterfly from laying the eggs that hatch on the plant and become voracious eating machines aka cabbage white caterpillars.

But I’m prepared to be convinced. Especially if it reduces the need to weed between rows and pick or wash off pests. So tell me - do you companion plant, and if so, what works for you?

Marigold by *micky

Labels: allotment-companion-planting, allotment-flowers, allotment-pests, allotment-vegetables