RHS TECHNIQUE: POTS & POTTING
RHS Horticultural Advisor Anne Adamis on hand to discuss the best pots to improve your growing performance
Growing vegetables and fruit in pots is fun, easy, makes the best use of small spaces and is a very good option for renters. With such a wondrous choice of pots and containers available, it is sometimes baffling to know which size or type of pot will be best, so here are some tips.
Types of container
Durable terracotta and stone pots can be heavy to move. Always look for terracotta assured to be frost-proof. Metal pots can get quite hot meaning the compost dries out quickly but have a contemporary feel, so ensure they are shaded or lined with some insulation. Wooden half barrels and boxes are great for longer-term plantings like fruit trees and bushes.
Vegetables like salad leaves will grow well in pots, troughs or grow bags, provided they are at least 15cm (6in) deep. Strawberries too grow well in shallower troughs. More substantial veg like tomatoes, chillies and peppers need to be potted up in stages into their final pots which should be around 30cm (12in) in diameter. Larger tubs accommodate three plants and can make striking patio features.
For most fruit, choose pots at least 45-50cm (18-20in) in depth and width. Anything bigger is very difficult to move, so needs to be sited with care.
Containers with a convex outline i.e. a narrower neck than middle may look attractive but could prove difficult if trying to repot a plant that has outgrown its container.
Re-purposing household items such as old boots, watering cans, and baskets, or even old clothing makes amusing, fun containers. Don’t forget to pierce ample drainage holes.
Generally, go for bigger containers, bearing in mind any need to move them. Smaller containers tend to dry out quickly needing frequent watering and feeding. Where smaller containers are necessary consider self-watering ones that have a reservoir of water which keeps the rootzone topped up without water-logging.
Planting up
When planting, place crocks (small pieces of broken clay pots) over the holes in the bottom of containers with large drainage holes to retain potting media during watering. Don’t use too many as you want as much compost for the roots as possible. Crocks won’t improve drainage however, so choose open textured potting compost.
Good-quality peat-free John Innes No 3 compost, or peat-free,
