Nearly all plants need a constant and regular supply of water for their roots to absorb. If this is interrupted plants start to wilt and can eventually die.

Frost and cold weather can damage numerous plants, but especially tender plants that can’t tolerate low or freezing temperatures and tender, new growth in spring.

Calcium deficiency isn’t common, and can be difficult to diagnose, but is responsible for two main disorders – blossom end rot in tomatoes and bitter pit in apples.

Boron is a micronutrient, needed by plants in small amounts. A deficiency can cause poor and stunted growth and a range of other symptoms, depending on the plant.

(Plasmodiophora brassicae) Clubroot causes swollen and distorted roots and stunted growth of brassicas – broccoli, Brussels sprouts, cabbage and cauliflower, including swede and turnip.

(Phoma clematidina – or physical damage) Clematis wilt disease causes clematis plants to wilt rapidly. However, most suspected cases of wilt are actually caused by physical damage to the stems.

(Monilinia laxa and M. fructigena) Brown rot is a fungal disease of fruit – especially apples, pears and plums – causing the fruit to rot. Shrivelled “mummified” fruit remain in the tree, spreading the disease.

(Botrytis fabae and Botrytis cinerea) Chocolate spot is the commonest fungal disease of broad beans. It produces reddish-brown or chocolate coloured spots on all parts of the plant.

(Cylindrocladium buxicola and Pseudonectria buxi) Box blight is a devastating fungal disease of box (Buxus) plants. It kills the leaves, resulting in extensive bare patches, and affected plants die back.

(Poa annua) Annual meadow grass  is a common weed of lawns, beds, borders and containers. It sets a lot of seeds each year and so spreads readily around the garden.

Blossom end rot produces dark patches on the bottom of tomato fruits – as well as peppers and aubergines. This plant disorder is mostly caused by irregular watering.

Various bacteria Plant diseases caused by bacteria can be extremely damaging. Luckily, there are few that are commonly seen in the UK. They produce a range of different symptoms.