Vegetables in March

Although the weather is still uncertain during March, we have definitely reached a turning point. The middle of February usually marks the beginning of more growth amongst the polytunnel plantings—salads start regrowing after the winter harvests, and things like peas and spring onions get going, but so do the weeds—so be sure to stay on top of them in any polytunnel or glasshouse.
We have already started seed sowing for some of the polytunnel plantings, and for some of the early outdoor planting such as turnips, red russian kale, mustards, rocket, beetroot, spring onions and the like. However, this can all still be sown through March—we just like to try and get a few extra early plantings in if we can. Sometimes they work and sometimes it’s too wet and cold and they don’t really take off. We make sure that we cover all of the early plantings outside with horticultural fleece, and we keep this on right up until the end of April at least. We just lay the fleece directly over the crops, pulling it tightly over them and then holding it down with sandbags around the edges. Most crops grow well under the fleece through early spring, and don’t mind it laying directly on their leaves as long as it is pulled tight over them and not allowed to flap around in the wind too much which can cause damage to the leaves.
We have a dedicated propagation polytunnel with heat benches to start off our sowings, which allows us to start the sowing a little earlier. These benches have small tunnels built over them to keep the seedlings warm and keep the humidity high to aid germination. We sow most of our vegetables in trays of the same size, which fit perfectly on the benches, so that we can maximise the heated space. Once germinated, the seedlings come off the heat benches and onto cold benches in the tunnel. These are covered with fleece at night to protect them from any frosts.
We mostly multisow each cell and do not thin these out before planting, but instead plant out clumps of plants together. For example with beetroot, chard, onions, salads (except for individual lettuce, chicory and endive), turnips, herbs like coriander, basil, dill, parsley and peas are all sown with a few seeds per cell—somewhere between 2-5 seeds depending on the crop. We even sow spring onions with about 10 seeds per cell, so that they grow in bunches and then we can just pull up the whole bunch in one go. This also allows for easier weeding/hoeing of the crops as we plant them out at standard spacings rather than if they were sown directly in a solid row, so we can hoe not only along the rows, but between the plants in the rows too. This makes a big difference at the beginning of the plants life, so that it can establish without competition from weeds growing around it.
A couple of important things to consider when propagating your own vegetables are light levels and airflow. It is important for seedlings to get maximum light levels reaching them so that they grow strongly, rather than with spindly stems searching for the light. It is also important to have good airflow around the seedlings to discourage any fungal diseases such as damping off which can become a problem in areas of high humidity and poor airflow. Either open up any propagators that you use or have a fan circulating the air around the propagating space to improve airflow around the seedlings. This also encourages them to grow stronger stems as they acclimatise to the air movement. If all this is too much, don’t worry—you can still buy in plants for your veg plot, just try to find organically grown plants if you can—there are a few places online that you will be able to find these.

WHAT TO SOW THIS MONTH: turnips, chard, spinach, salad leaves – chervil, buckshorn plantain, lettuce, burnet, peashoots, anise hyssop, kales, mustards, agretti, sorrel, summer purslane & goosefoot (end of month). Radish, fennel, courgettes (end of month), spring onions, beetroot, cucumbers, early tenderstem broccoli, dill, coriander, peas and mangetout. We sow all of these into trays in the propagating tunnel to be planted out in April mostly. Also all of the indoor solanaceae such as tomatoes, peppers, chillies and aubergines can be sown now, as well as indoor grown french beans.

WHAT TO PLANT THIS MONTH:

OUTSIDE: salads—mustards, rockets etc., lettuce, peas, broad beans, potatoes, early kale.

INSIDE: If you sowed any early salad crops for a polytunnel or glasshouse they can go in at the beginning of March. Also successions of peas and spring onions will continue to be planted.

OTHER IMPORTANT TASKS THIS MONTH: If the weather dries, continue preparing beds for the spring by mulching with compost. Keep on top of the seed sowing, but don’t sow too much of anything—think about sowing successionally rather than doing one big sowing in early Spring. Things that are perfectly suited to successions include all salad leaves, spring onions, peas, beans, beetroot, chard, kale, carrots, fennel, radish and annual herbs.