Growing fruit indoors

After years of growing my own fruit and veg in window boxes and on sills, I have found that some plants are better than others for indoor growing. As I work full-time, I also needed plants that wouldn't take too much time, or die if I failed to water them precisely on schedule.

For this article, I am focusing on plants that are compact, relatively low maintenance and that fruit all year round: suitable for a beginner or someone who hasn't considered this before.

While there are many dwarf varieties of trees: citrus, cherries, even pomegranate, I'm not covering them here. Almost all of them are designed for patio growing in containers, and are too large to be brought indoors. The challenges facing a gardener who has somewhere outdoors to work with, even if it is a square of concrete, are very different to those facing someone on the twentieth floor, with windows that hardly open.

This article therefore focuses purely on plants that can be grown entirely indoors. 

These citrus trees produce a small fruit, rather like an tiny orange. However it is sour and tastes like a lemon (good with sugar on pancakes!).

It is ideal for growing indoors in cold climates, or if you don't have access to a garden. Its growth can be restricted simply by keeping it in a small pot, and if kept well watered, it can fruit all year. Like most citrus it does like a lot of light, and needs to be kept warm for best results. Small plants can fit on windowsills, while larger versions can be used to replace ornamental trees or free stand in corners.

It does not drop leaves often and is an easy plant to keep tidy. The flowers are attractive, so it can also brighten a room up nicely.

Nutrition-wise, it is a very healthy fruit, high in vitamin C and other benefits.

Many of these plants can be bought as adults, so you can instantly get fruit from them. However you can also buy seeds to grow from. This is not fast - while for a strawberry you can wait a year for fruit, for a citrus it might take six. So shy grow from seed?

First, grafting. While grafting fruit trees onto sturdy root stock is normal, less ethical grafters will take the end of a fruit bearing limb with no growth buds, graft it onto a mismatched or poor quality root stock and expect it to last a year. These can be twisted onto concealed frames to make sure they look like trees, and aren't healthy.

Second, pests. Adult plants can come with pests like aphids or scale. If you grow from seed yopu can keep the growing environment largely free of these, which reduces any chance of these problems showing up.

Finally, seeds can be had for free. I have an avocado and several tangerine trees on a window sill, by saving seeds from lunch. This type of fruit rarely breeds true, so in a few years I'll be very curious to see what their fruit is like.

The best thing about them is that fertiliser is simple and organic: tea leaves. Like all strawberries, Alpine strawberries love nitrogen, and used tea leaves contain plenty of it. Just don't over-fertilise or it will produce a lot of folliage and no fruit!

You can grow raspberries indoors. These are not ever-fruiting, although you can encourage a second crop, but the leaves can be used for raspberry-leaf tea.

However, this isn't really one for a beginner as the plant can get rather large, and to produce fruit requires manual fertilisation (rubbing the flowers together, or using a paintbrush to transfer pollen from one flower to the next). If you are fond of raspberries you can try it, but this is a much larger commitment.

The same is true of gooseberries and many other fruit bushes. While you can grow them indoors, they are a lot more work than the plants I've suggested above.