Feeding and Watering Soft Fruit Plants
FOOD AND WATER
The key to soft, succulent and tasty fruit is adequate moisture (after all, a large proportion of the volume of any fruit is water) and appropriate nutrients. In addition to sunshine and warmth, it is usually a shortage of water and appropriate food that makes for disappointing crops in gardens.
I stress appropriate food, for it’s important to appreciate the differences between the role that each nutrient plays. In very simple terms, nitrogen encourages the growth of leaves and other green parts, a most important attribute because only green tissue can photosynthesize and so lead to vigorous growth overall. Phosphate is most important in st15cmating root development which means secure anchorage and the effective uptake of mineral substances from the, while potash encourages flower and fruit formation. For a fruiting plant therefore, the value of potash is self-evident but it is important to achieve the correct balance, with sufficient nitrogen being given to ensure that the plant as a whole is strong and vigorous, but not in such large doses that the foliage develops at the expense of the fruit.
Although commercial fruit growers use rather complicated feeding regimes for each type of fruit plant (and sometimes, even for individual varieties), far less critical standards are needed in gardens. Over the years, I have found that my soft fruit garden needs are satisfied by two principal fertilizers and the advice in the individual entries is based around these. A balanced general fertilizer, applied once a year will be perfectly adequate to produce good soft fruit and my preference is for, blood and bone, which is an organically based mixture. An alternative would be an artificial mixture, such as Growmore. But this general fertilizer is ideally supplemented by potassium sulphate (often called sulphate of potash) for the best soft fruit production. A liquid fertilizer, such as the type sold for , will similarly supply a high dose of potash. If you have chalky soil in your garden, a proprietary product containing sequestered iron will be useful, especially for raspberries and which are highly prone to iron deficiency on alkaline soils. There may also be occasions, such as if a plant has been neglected, when a boost of nitrogen is much needed and dried blood or ammonium sulphate (sulphate of amonia) will provide this.
Mulching is a technique that still engenders a wariness. I think this stems from a disbelief that several centimetres of compost or other organic matter laid on the soil surface won’t be positively harmful to the plants. Be assured that it won’t. I routinely lay 10- 15cm (4-6in) of compost on my light soil around the base of soft fruit canes and bushes twice a year, in spring and autumn. It serves its purpose of moisture retention and weed suppression but within three or four months (even less in a hot summer), it has vanished; dragged into the soil by worms, oxidized into carbon dioxide or used by plants as a source (admittedly a modest source) of nutrients.
Mulching as a weed suppressant achieves its effect by denying the weeds the light that they need to thrive. Whilst the shoots of a deep-rooted perennial will still have the energy to force its way upwards, the tiny food reserves available to an annual weed seedling mean that it will die of starvation long before it is able to grow through a mulch to reach the light.
An alternative mulching method that has found some favour in recent years is black plastic sheeting. This obviously denies light to weeds and limits water loss from the soil surface. But of course it plays no part in the improvement of soil structure and to my mind, looks frightful. Having a fruit garden that is aesthetically pleasing is only slightly lower in my order of priorities than having one that crops well.
Water is very important to soft fruit plants and mulching with organic matter on already damp soil in both the autumn and the spring will help to maintain the soil moisture in a fairly uniform state. Even so, during very dry periods, supplementary water may be needed particularly at the time the fruit are beginning to swell. It can either be supplied by a watering can or more efficiently (and if permitted) by a sprinkler or a trickle irrigation system. But don’t waste water; do limit it to the period when the fruit need it, when they are filling out, and don’t apply it wastefully between the plants rather than where it is needed — which is around their bases.
When water usage isn’t legally restricted during drought periods, a sprinkler offers the best method of supplying supplementary irrigation to your soft fruit garden. But do choose a sprinkler that offers the best coverage for your purpose – far too many gardeners use sprinklers that give a circular pattern of spread to water a rectangular area. In consequence, some parts are missed altogether while water is thrown wastefully over neighbouring paths or perhaps even over the wall onto someone else’s patio! Do measure the area that you wish to irrigate and then check carefully the pattern of spread before buying a sprinkler.