October is the month for apple festivals, when National Trust gardens, nurseries, farms and orchards invite the public to taste and buy hundreds of different home-grown varieties, and get tips from top growers on how to reap the best harvests.

We grow more apples both commercially and in the garden than any other fruit tree. Indeed, Apple Day, started by charity group Common Ground, celebrates its 25th anniversary this year on October 21, so there’s no better time to start growing your own.

Most apples sold today are grown on dwarfing rootstocks prefixed with the letter M (for Malling, the Kent research station where they were developed from the 1970s). Dwarfing rootstocks, like M26, keep the tree small, under 3.6m (12ft) tall and slow-growing. They also crop early on in life, within a year or two of planting.

However, very dwarfing rootstock, which produces slightly smaller trees, needs extremely fertile soil, regular watering and yields are lower. So if you have room, you may want to choose a slightly larger tree.

Trees grown on dwarfing rootstocks need to be supported by a strong stake, as their roots are not massively strong. You’ll need to keep a 90cm (3ft) circle around them of bare soil which is free of weeds and other plants. With more vigorous trees, that area needs to be kept free for three to four years while the tree becomes established, after which time you can grow grass around it.

Apple blossom needs to cross-pollinate with one or two other varieties to set fruit, but usually there will be enough apple trees in the area to ensure a crop. If there aren’t other apple trees in the vicinity, you may have to grow another variety which flowers at the same time. Alternatively, grow a self-fertile variety such as ‘James Grieve’ or ‘Cox’s Self-fertile’.

You can also buy family trees, where two to four different but compatible varieties are grafted on to one tree, ensuring cross-pollination and a longer cropping period.

Container-grown trees can be planted all year round, but bare-rooted trees should be planted while they are dormant, between November and March. Free-standing trees, grown in the open without any horizontal support, are by far the easiest to maintain.

Prepare the site at least a month before planting, double digging to aerate the soil and create a 1m (3ft) square plot where each planting is to take place. The most common mistake is to dig a hole too deep and too narrow to house the roots properly.

Dig a hole large enough for the roots to spread easily and knock in a stake at least 30cm below the bottom of the planting hole on the side from which the prevailing wind blows.

If the roots of your bare-rooted trees seem dry, plunge them in a bucket of water for a couple of hours before planting. Then plant the tree so the old soil mark on the stem is just above the top of the planting hole.