Iris Jardine looks at the seasons and provides a list of 'essentials' to either jog your memory or help you create the garden you have always wanted
Spring is the time when the earth wakes from its winter lethargy and growing things begin to stir in the ground. Early-flowering perennials should be coming up, such as dicentras, Solomon seal and irises, and of course, trees are coming into blossom.
To encourage plants to grow, it is important to feed and mulch. A layer of decomposed organic material 2 to 3 inches (5 to 8cm) thick, such as compost, needs to be added regularly to improve soil structure. You can also use a general-purpose fertiliser, unless you have a plant that you know will need a special type. There are different grades of mulches for different purposes. Coarse bark is good for areas around trees and larger shrubs, while a finer one is more suitable for small plants and vegetables. If you have been making your own, this is now the ideal time to use it, provided it has had at least a year to compost down. Another benefit of mulching is that it wards off weeds, although the downside is that it won't allow your plants to self-seed. For plants, where you want them to self-seed, surround them with gravel or put them near loose paving stones where there are cracks with soil in them. Weeding, preferably using a hoe, needs to be done at this time.
A must before planting is to define the type of soil you have by checking out its pH levels. This, more than anything, will define what plants will flourish and grow, and is often the reason for healthy plants wilting and dying. For example, acid-loving plants such as rhododendrons and camellias would go yellow and die if planted in an alkaline soil. Testing in one area is not enough; there is every possibility that, at some time, builders have dumped waste in the garden, and this would make a difference to the soil. Take the soil from at least five different areas, mix it in a bucket, and take your sample from this. Testers are not expensive, well under £1, and can be bought at your local garden centre. Soil varies between acid and alkaline, taking pH7 as neutral. Numbers below indicate acid soil, while those above are alkaline. Most garden plants prefer a slightly acid 6.5. To raise the alkaline level, add lime. Alkaline soils can be made acid by adding sulphur. Generally, this is too slow and expensive a practice to be worthwhile; better to grow acid-loving plants in containers of ericaceous compost, where the soil is alkaline.
Once your type of soil has been established, sun and shade come into play. Plants need light, heat, air and water to grow, and it is important to position your plants according to whether they are sun or shade loving. Guy Barter, Senior Horticultural Adviser of the Royal Horticultural Society, suggests grouping plants with similar needs - drought resistance or requiring moist soil, for example - so that watering and feeding is simplified.
For the majority of seeds, early spring is the time to sow them in pots. If you don't have a greenhouse or big enough ledge, it is best to leave them for an extra four to six weeks and sow your seeds, still in pots, outside. Although pottery ones look prettier, plastic pots, produce better plants. Once the seeds start to sprout, 'prick them out' - that is, take single seedlings and carefully plant them individually in bigger pots, or trays that have already been sectioned into individual compartments.