Planting decisions in a vegetable-garden are tricky because you are trying to avoid leaving the soil bare between one crop and the next. Crop rotation and the needs of each crop are two more factors that you need to consider
Preparing your new vegetable-garden for planting is best done over the winter and early spring.
Planting – Preparing the Soil
Cover the bed with heavy-duty black polythene the fall before you intend to start your spring planting. This will stop all the weeds getting light and most will die. In late winter remove the polythene. Spread a thick layer of compost over half the garden and dig the vegetable-garden thoroughly. Only cover half the garden with compost because there are some vegetables that dislike fresh compost in the soil.
Your soil should, ideally, be deep and rich, with lots of organic matter in it. It will probably fall short in at least one of these requirements. Any deficiency needs to be put right before you start planting.
Consider buying a truckload of soil, if your soil is not at least 6 inches deep.Buy the best topsoil you can find and do it sooner, rather than later, because the soil needs to settle. If you end up with a raised bed, you will need to construct a retaining wall. A simple way to do this is just to wedge stones, vertically in the sides of your raised bed. Field boundaries in Ireland are built like this and they have stood for 300 years.
If your soil is deep enough, add compost to it and plenty of slow-release organic fertilizer such as a Blood, Fish & Bone mixture or Bone Meal. Most artificial fertilizers are water soluble, organic ones are much less soluble, so they deliver smaller concentrations of essential nutrients over months or years, rather than a dew weeks.
Deciding What to Grow
Everyone has likes and dislikes amongst vegetables, but start by growing ones that are expensive at the supermarket, such as spinach and turnips, ones you cannot buy, such as fresh peas and ones that are easy to grow for your first year. Peas, potatoes and onions are the easiest, so start with those. Plan to follow these with leeks, broccoli and cabbage.
Browse seed suppliers' websites and catalogues. The suppliers' catalogues give details of planting times in different areas and you can plan your vegetable-garden, month by month. Look for different varieties of vegetable, like purple carrots for added interest.
Buy seed potatoes, leave them to sprout on a windowsill. This 'chitting' means that your potatoes get off to a faster start, so it is well worth doing. Just stand the seed potatoes so most of the 'eyes' are uppermost.
Sow broad beans outside in about 2 inches deep. If mice and rats are a problem, then sow them in troughs instead and transplant in April. (The lip on a trough stops mice getting in.)
Sow tomato seeds indoors on a windowsill in damp compost. Use divided seed trays so you can pot them on without damaging the roots.
Plant your seed potatoes towards the end of the month. In Ireland seed potatoes for new potato crops are planted on St Patrick's Day, March 17th. The exact date depends on where you live.
Sow celeriac seedlings in peat pots on a windowsill inside the house.
Sow carrots, thinly in rows, cover very thinly with soil. Alternate rows of carrots with rows of spring onions to keep carrot fly away.
Sow parsnip seeds
Sow celeriac now for a crop all winter long. Celeriac is a vegetable that is always expensive and not universally available, so, grow your own.
Transplant tomato seeds to individual pots, but keep them indoors until all risk of frost has passed.
Sow peas in troughs. The lip on a trough stops mice getting to your peas.
Sow cabbage, broccoli and cauliflower seeds in troughs. Put the troughs close to the house where rabbits are less likely to eat the seedlings.
Sow onion sets about 6 inches apart.
Plant a row of spinach seeds, where you can reach them easily to harvest the leaves.
Plant turnip seeds, too, but sow them very, very thinly.
Sow leek seeds in a bucket or trough, they stand up to drought better and develop better root systems than if you plant them in seed trays
Move celeriac seedlings outside.
Transplant peas to the vegetable-garden. Stand twiggy sticks between the pea plants. Even though they are not supposed to need support the peas grow better with it. Sow more peas for a later crop.
Sow more beetroot seeds thinly and cover very lightly.
Sow runner beans and French beans in small pots.
Thin out your turnips. If two turnips are immediately adjacent the growth of both will be stunted.
Single-up the celeriac seedlings and transplant them to the ground.
Harvest new potatoes, do not wait until the tops die down for new potatoes.
Transplant leeks as you lift the potatoes. Use a dibber to make a hole about 6 inches deep, drop one leek seedling into each dibber hole and fill up the hole with water.
Harvest peas, spinach and turnips, dig up the last of your new potatoes
Plant any remaining leek seedlings
Harvest runner beans as soon as the pods are four or five inches long. If just one pod escapes harvest and grows to maturity the plant will stop producing flowers and new beans
Plant out cauliflower and winter cabbage seedlings, where onions were.
Sow spring cabbages, kohl rabi and turnip
Harvest last of runner and French beans
Harvest late peas
There is no planting to be done just harvest vegetables when they are ready and remove large weeds.