This month in your Garden - April
April is one of the best and busiest months of the gardening year. As the days lengthen, plants begin to grow at a seemingly fantastic rate and even the best organised gardens can feel like they are slipping out of control…
Weeds start to grow apace this month. A sharp hoe is perfect for dealing with large numbers of fiddly seedlings, but choose a dry day and take care not to damage the plants you want to keep.
Having weeded, apply a mulch of organic material at least 5cm thick to smother any survivors, conserve moisture and improve soil structure.
Prune lavender and other slightly tender evergreen plants like penstemons and hebe. Always cut above healthy buds or shoots as these plants tend not to grow well from bare wood. Very old or straggly plants are best replaced - fortunately this is also a good time to plant them.
Hardy annuals can be sown outside whenever the soil is dry enough to rake into a fine, crumbly tilth. I prefer to sow in evenly spaced rows as the emerging seedlings are then easy to distinguish from weeds. The initially rather regimented look is quickly lost as the plants grow into each other.
Erect supports for herbaceous perennials now, as the job will be much harder once your plants have begun to flop. Twiggy brushwood saved when pruning shrubs and trees provides excellent support for most perennials, without the need for twine or plant ties.
Many vegetables can be sown this month, including:
- carrots
- beetroot
- peas
- broad beans
- swiss chard
- perpetual spinach.
Erect supports for peas and broad beans. Twiggy brushwood is the traditional choice, but stout stakes and netting are more easily available and just as good. Dwarf varieties such as broad bean ‘The Sutton’ do not need support, and are a particularly good choice for small or exposed gardens.
Slugs and snails will be on the march as the weather warms up, so protect vulnerable young plants with slug pellets, copper rings or barriers of grit. Nemaslug, a widely-available product containing naturally occurring parasitic nematodes, gives useful control of slugs (though sadly not snails) but must be applied when soil temperatures are above 5˚C.
Glasshouse
Ventilate greenhouses and cold frames on sunny days, but be sure to close vents and doors as the temperature drops in the late-afternoon. Consider installing a simple automatic vent opener to do this job for you – most are inexpensive and do not require an electrical connection.
Continue to prick out seedlings as soon as they are large enough to handle. Plants pricked out into trays or small modules should be potted on into larger containers before their roots become congested.
It's safe to move hardy annuals outside as soon as they have formed strong plants. If the weather is mild at the end of the month, move half-hardy annuals to a cold frame to begin the process of hardening off. Bear in mind, however, that these plants can be damaged by sudden drops in temperature and frost will kill them outright.
Lawns
The mowing season begins in earnest this month. It’s tempting to cut a scruffy spring lawn short in one go, but this can turn it yellow. Make the initial cut with the mower blades set high, reducing the height gradually over the course of a few weeks.
April is the best month to apply lawn feeds and weedkillers. Whilst these are essential to maintain high quality turf or restore neglected lawns, many people find they are able to grow a perfectly acceptable patch of grass without either. If you do decide to feed and/or weed, it’s worth taking time to apply the product evenly to avoid uneven growth or scorched patches.
Repair bare patches or establish new lawns from seed or turf. Be prepared to water, however, as the top layer of the soil can dry out surprisingly quickly.
