Once you have established what plants will thrive in the conditions in your garden, you can prepare to make your selection with confidence. Plants are living, perishable things, and supplies will often fluctuate widely according to season and what the commercial growers decide to market. The condition of the plants is also never certain, though there are certain signs to look out for to ensure you are choosing a healthy specimen.
Plants are sold in different places, from supermarkets to nurseries, and they will have received different levels of care. Those sold on the same site where they were raised are likely to be younger and healthier than those which had to endure a journey to their destination. As they are transported, plants may undergo a period of drought, which will affect their growth.
Conditions at the point of sale also affect the health of plants: the longer they remain unsold, the more they will begin to suffer as the reserve of slow-release fertilizer in their pot runs out.
Nurseries are a good choice for specialized and more unusual plants, and expert advice on choosing and caring for them. The selection in garden centres is improving and they stock a wide range of plants.
Before buying a plant inspect it for signs of pests, disease and damage. Leaves should be free from holes, bitten edges, wiggly patterns across the middle, yellow patches (unless it is variegated) or brown spots, and they should feel firm and should not be floppy. Stems should also feel firm, with no signs of being eaten, and no small, oval, brown bumps (scale insects) on them. Look for signs of fungal attack, particularly the tiny coral-coloured spots of Nectria cinnaharina, a fungus that will attack both live and dead wood and can easily kill a young plant.
If the compost (soil mix) is covered with weed seedlings, moss or liverwort, the plant has most likely spent sometime in the same place and is likely to be under-nourished.
The plant may also be pot-bound, a condition in which the roots circle round and round inside the pot. The plant may find it hard to break this habit, leading to a poorly anchored plant that will be susceptible to being blown over in a high wind. The roots of a healthy plant will be fat and swollen, and white, yellow or chestnut-brown, but they should not be shrivelled or dark brown. Don’t be afraid to knock the plant out of its pot to inspect the roots.
Often, newly potted plants are on sale alongside ones from previous deliveries that have not yet sold; younger ones will establish such more quickly, even if they are slightly smaller to start with. Don’t be fooled – biggest is not best in the world of plants!
Aphids are the best-known plant pests. Greenfly and blackfly are the most common ones, but there are many species, some affecting the roots of plants rather than the leaves.
Some commercial growers supply plants by mail order. These plants are usually dispatched in lightweight but highly protective packages, and the quality is often quite high.