Gardeners are being encouraged to purchase two varieties of plants from nurseries now. However, they are being cautioned against planting them immediately in case we experience another cold spell.

Gardeners' World presenter Joe Swift says we are "fast approaching" the period when tender annuals and herbs should be planted. Nevertheless, Joe advises holding off placing them in the ground just yet. Writing in The Times, he said: "Buy them from the garden centre and nurseries now but, depending where you live, perhaps don't plant out for another two weeks. If you do, watch out for a cold snap."

Joe explains that annuals are typically sold in pots or strips. The climbing varieties, such as sweet peas, morning glory, Spanish flag, and black-eyed Susans represent "great value" choices.

He notes that some of these can grow up to three or four metres in height and will keep flowering throughout the summer months. The plants also provide a solution for borders lacking vertical interest, Joe explains.

He said: "For borders that lack height, consider making a wigwam from bamboo or hazel canes - push them into the soil and tie them together at the top, then grow a climber or two over."

However, Joe says hardy and tender annual flowers, such as cosmos, nicotiana, snapdragons, nigellas, and poached egg plants can be planted directly now. As can annual herbs like basil and coriander alongside hardier herbs such as mint and chives.

Joe explains that many of these plants are simultaneously "ornamental" and "tasty". The RHS notes that fresh herbs are "easy to grow" and provide an extra burst of flavour to mealtimes once harvested.

The society advises that herbs should be cultivated in full sun with ample light, in well-drained yet moisture-retentive soil. Seeds for plants such as coriander and dill should be sown on a fortnightly basis throughout spring and summer.

Gardeners are encouraged to plant several herbs with varying maturation times to maintain a productive herb garden. Meanwhile, herbs such as chives, mint, parsley and tarragon should be grown outdoors and brought inside during winter.

Hardier herbs such as mint and sage are best potted in larger containers, while those with limited space may find a grow bag particularly useful. Herbs planted in spring can be sown beneath cloches and frames, according to the RHS.

Alternatively, gardeners can sow trays in a greenhouse, conservatory, or on a sunny windowsill, ready for planting once the soil warms up. Certain herbs, including lavender, sage, thyme and rosemary, can fall prey to the rosemary beetle.

Young seedlings may also require protection from birds, slugs and snails, while other herbs such as dill and basil can struggle when overcrowded.