While there are some peach varieties that can be grown outside in southern reaches of the UK, a polytunnel will allow gardeners further north to enjoy this delicious fruit. A polytunnel can give the necessary protection from frost for the blossoms and then fruits early in the year. It can also provide a degree of protection from birds and mammals who also enjoy eating these juicy fruits.
In the UK, it is easiest to grow peaches in containers, so these can be moved to a warmer location when required. Alternatively, you may choose to grow peaches directly in the soil in your polytunnel. Peach trees can be trained to fit into a smaller space. It is best to plant peaches during the dormant period, between November and early spring. In a polytunnel or under glass, blossom can appear as early as February so you may need to provide extra protection against frost in an unheated tunnel.
Since peaches flower so early in the year, it is unlikely (unless you keep your own bees) that there will be enough pollinating insects about to pollinate them. To pollinate by hand, on a sunny day, take a small brush and gently press the bristles into every flower. Do this on several afternoons and you should get some fruit.
It is extremely important to water your peach tree well and ensure that the roots do not dry out completely at any point. During the growing season, you should water almost every day, reducing water given during the dormant season. A good, potash-rich, organic mulch will help to retain soil moisture and will help feed your tree.
When fruits appear, these should be thinned to give a final spacing between fruits of around 15cm. Remove any small or misshapen fruits when they are around the size of your fingernail. Keep an eye on fruits and if necessary, protect them from birds and other wildlife. Prune your tree as required for shaping or to keep it within bounds. The aim of pruning is to replace fruited wood with new growth. Peaches mostly grow on the previous year's growth.
Peaches should be ripe and ready to harvest between July and September. Peaches will be ready to pick when they are fully coloured and the flesh close to the stalk feels soft. Cup each fruit in the palm of your hand and then lift gently. You will need to harvest over a long period as not all the fruits will develop at once. Do not leave picked fruits uneaten for too long. Peaches are at their best eaten fresh, straight from the tree.