March 27, 2009 In the Garden

• If you see white butterflies hanging around your vegetable patch, odds on they are laying eggs on your baby brassica plants. Early intervention means you can usually rely on digital control (don’t be squeamish – squash the caterpillars) but if you let them get away on you they will either ruin your crop or you may have to resort to chemical control. Covering the plants with fine netting can keep the white butterflies away but you really need to build a temporary frame to hold the netting away from the plants and to get rid of any eggs and caterpillars already present. There is nothing more likely to discourage children from eating broccoli than coming across boiled green caterpillars in it (the voice of experience here) so it is worth trying to keep the plants clean. You can still be planting brassicas and other leafy greens for winter harvest.
• Celery and leeks are two vegetables which are better with pale stems (the greener they are, the tougher they get) so if you have them in the garden you can earth up around the stems to blanch them.
• If you are digging carrots with holes in them, the culprit may be weevil or carrot fly. Sometimes slugs will also have a go at getting in on the act. It is too late to solve the problem now and we just cut the bad bits out. You can’t do anything about weevils and dealing to carrot fly is hit and miss where recommended treatments tend to be heavy duty insecticides like Diazinon. Late plantings tend to escape carrot fly and look for varieties which are marked as resistant. Well cultivated soil discourages weevils in the longer term.
• Readers who have nice tidy hedges bordering garden beds may pale at the prospect, but rootpruning close to the hedge is advisable. This is just making a deep cut with a sharp spade to stop the hedge roots making inroads to the garden beds. It is even more important if you have a cutsie potager with small beds, because all that hedging robs the goodness from the soil. Really organised or experienced gardeners know to lay a barrier of non rusting iron or similar just below soil level when they first plant the hedge, so containing the roots. But most of rely on the occasional root prune.
• While the dry weather continues and there is some heat in the sun, get out with the push hoe for weeding and to till the top layer of soil. If you rely on spraying weeds with glyphosate long term, you end up with soil which becomes compacted and often develops a top skin of moss or liverwort. Breaking this up with a push hoe aerates the soil as well as giving a more cared-for appearance. Once the autumn and winter really set in, the push hoe is not as useful because you also have to rake up the debris (the sun isn’t hot enough then to dry it for you). Mark, who is on crutches this week and therefore developed cabin fever by the second day, is pondering whether he can attach the push hoe to a crutch and remain active that way.
• Random information from the Curious Gardener’s Almanac: the honeybee kills more people around the world each year than all the poisonous snakes combined, but the creature responsible for the most human deaths worldwide is the mosquito, by a considerable margin.