How to Grow Salvias

The Genus Salvia contains a staggering 900 species – some of those being the most highly ornamental in the entire plant kingdom. At Dysons Nurseries our main interest lies in the New World species and cultivars i.e. those from Mexico and the southernmost states of the U.S.A. These plants are notable for their often-considerable flowering period and a diversity and intensity of flower colour seldom equalled in other genera. Some are hardy in the southern counties of Britain whilst others are tender and require glasshouse protection over winter, but all are immensely garden worthy and merit much wider cultivation.

Following is a brief guide to the cultural requirements of the Salvias that we offer at Dysons Nurseries.

All recommendations are based on our experience of growing these plants here in the North West of Kent over the past 14 years on well-drained sandy soil with minimum winter temperatures of approximately minus 10 degrees Celsius.

There are, broadly speaking, four distinct categories of Salvias in our list, these categories are determined largely by overwintering requirements. However, two requirements that are common to all of these plants are a well-drained soil or compost and as much sun as possible. Unless protection is available planting is usually best carried out between May and August, this gives the plants chance to build up a good root system and ripen their wood before the onset of winter.

Overwintering Categories:

1. Shrubby Salvias that are hardy in Kent. These include SS. greggii, microphylla, x jamensis cultivars and S. chamaedryoides.

2. Hardy herbaceous Salvias. These include SS. nemerosa, staminea, x superba and x sylvestris. The plants in this group are generally regarded to be fully hardy throughout the United Kingdom. They are generally late spring and early summer flowering plants, however, reblooming can be encouraged by cutting back to just above ground level immediately after their main flowering period. Cut back again in either autumn or early spring.
3. Half-hardy herbaceous Salvias. These include SS. arizonica, blepharophylla, patens and sinaloensis.

This category require a more sheltered position than the above but are otherwise reasonably easy to overwinter. S. sinaloensis will sometimes succumb to winter wet though.

S. patens can be mulched during the winter to protect the tubers from frost or the plants may be cut back, lifted and overwintered in a cool, frost-free place pretty much as for Dahlia tubers.

4. Half-Hardy and tender, shrubby and woody-based Salvias. This category includes SS. confertiflora, corrugata, dombeyi, dorisiana, fulgens, leucantha, miniata,

semiatrata, splendens and urica. Apart from those fortunate enough to garden in mild coastal or sheltered London gardens, the rest of us have to give these plants a ride in a wheelbarrow to more congenial winter quarters. Indeed several are triggered into flowering by the shortening daylengths of autumn and winter thus making them excellent subjects for the conservatory, often blooming well into the spring. The pruning of this group is generally a matter of shaping and the removal of spent inflorescences.