March heralds the start of the spring however in Scotland the weather can still be very cold and frosty. Gardening books and seed packets give a range of crops that can be sown from March onwards. In Scotland this advice should be treated with caution. It is best to sow seed once the soil has had chance to warm up. Delay the bulk of seed sowing until April, May and June.
Crops that do germinate at low temperatures include broad beans, peas and some brassicas such as cabbage, kale and radish. When the ground is workable (not too wet or frozen) these can be sown outside in March. Cover with a cloche or fleece to provide some extra protection from the elements.
If your garden is particularly warm and sheltered or you have a polytunnel or greenhouse it may be possible to sow a range of other hardy crops such as beetroot, carrots, chard, lettuce, parsnips and spinach.
Tomatoes, chillies, leeks, celery and celeriac will not germinate at low temperatures but can be sown on a warm window sill or heated propagator to ensure that they have a long season to grow.
Towards the end of the month, if the soil has warmed up, it is time to start planting early potatoes, onions and shallot sets. Early potatoes need protecting from frost so mound up the soil over newly emerged shoots (known as ‘earthing up’) or cover with a fleece if frost is forecast. Newly planted onion and shallot sets need protecting from birds that have a habit of pulling them out of the ground. Cover with a net until they are established.
Other tasks for March include:
- Finish preparing soil; remove perennial weeds and apply organic matter
- Dig in overwintering green manures so they have chance to breakdown before spring seed sowing
- Erect supports for peas and beans; make sure they are strong enough to withstand high winds
- Last chance to carry out winter pruning and plant bare root fruit trees and bushes