How to Grow Salvia

Hunker may earn compensation through affiliate links in this story.
Image Credit: agatchen/iStock/GettyImages

Salvia (​Salvia divinorum​), a member of the mint family, is easy to grow, but you'll have to pay special attention to what kind you get. These tender perennials are often grown as annuals but will grow as perennials if planted in the right place. With more than 1,000 types from which to choose, there's no doubt you'll be able to find perennial salvias that grow well in your area.

Blooming in blue, red, pink, purple, white and yellow, salvia flowers form their blossoms atop long, square stems. The flowers look like spikes and are actually a group of tiny flowers rather than one big bloom. Depending on the variety you choose, your plants will stand 18 inches to 5 feet tall, but they'll only get about 10 to 12 inches wide.

Best Uses for Salvia

Salvias work well as border plants and look absolutely charming when planted along white picket fences. You can plant a single plant or several, but salvia looks best when planted in groupings of three to five. You can also plant salvia in containers, where their height makes them an excellent centerpiece.

No matter where you decide to plant your salvia, expect the plant to attract bees, butterflies and hummingbirds. These pollinators are fun to watch and will help pollinate other plants in your garden that can't pollinate themselves.

How to Grow Salvia

  • Common Name:​ Salvia
  • Botanical Name:​ ​_Salvia divinorum_​
  • When to Plant:​ Plant both seeds and seedlings after the last frost
  • USDA Zones:​ 5-10
  • Sun Exposure:​ Full sun
  • Soil Type:​ Moist, well-drained soil
  • When it's in Trouble:​ Wilting, yellow leaves
  • When it's Thriving:​ Strong, upright stalks supporting flower spikes

Starting Salvia From Seed

You can plant salvia from seed if you like, and it's easy to do so. After the last frost has passed in your area, work some compost into the top 6 to 8 inches of soil. After working the soil, use a garden rake to smooth it. Drop your salvia seeds onto the ground and then barely cover them with dirt.

Water after planting and keep the seeds moist but not soggy until they germinate in 15 to 21 days. When they do, thin them so the young plants are about 12 to 18 inches apart. Mulch around your young plants to help retain water and prevent weeds.

If you're antsy to get back outside and start playing in the dirt, you can start your salvia seeds inside six to eight weeks before the last expected frost.

Starting Salvia From a Seedling

Salvia is easy to start from seeds, but planting young nursery plants isn't complicated either. If the potted plants from your local nursery are large enough, choosing live plants that have flowered will let you see exactly what color you're going to get.

To plant, dig planting holes that are large enough to comfortably accommodate the entire root ball of your young plants. Tip the seedlings out of their pots, loosen the roots a bit and then place the plants in their new homes. Backfill the planting hole and tap the soil down gently but firmly. Space the plants 12 to 18 inches apart. Water your new plants and mulch around them.

Image Credit: herreid/iStock/GettyImages

In What Zone Does Salvia Grow Best?

With so many varieties from which to choose, you can easily find a salvia that will grow anywhere in zones 5 through 10. Texas sage (​Salvia coccinea​), for example, grows as a perennial in zones 9 and 10. You can still grow this variety in colder areas but treat it as an annual plant if you do. The lovely May Night salvia cultivar (​Salvia sylvestris​ 'May Night') will survive as a perennial in zones 4 through 9, making it a good choice for Northern gardeners.

If you want a perennial plant but aren't sure which salvias work best in your area, visit your local garden center rather than ordering plants or seeds online. A local nursery will know what type of salvia grows best in your area and isn't likely to carry plants that perform poorly in your region.

When Should You Plant Salvia?

Salvia is best planted in the spring after the danger of frost has passed. Getting salvia in the ground quickly gives it ample time to establish itself before cold weather sets in. If you've selected a salvia plant to grow as an annual, you can plant at any time in the spring or summer. Just make sure to keep a close eye on your salvia's water intake if you plant during the summer heat. Your plants may need a little more water than they would if they were planted in the spring.

Soil, Sunlight and Water Recommendations for Salvia

Salvias prefer a neutral to slightly acidic soil but aren't that particular. Some varieties will tolerate a bit of shade, but most prefer full sun and do quite well in the heat, needing only about an inch of water a week.

Salvias are light feeders and often require no fertilization at all. If you feel your plants are underperforming, however, you can feed your plants a balanced fertilizer once during the spring just after new growth appears. Keep granular fertilizers away from the stem and crown of the plant to avoid chemical burns.

Deadheading spent blossoms will encourage your salvia to produce more blooms. If you like, however, you can leave the spent flowers on the plant in the fall so you can collect seeds or allow birds to feed on them during the winter months.

If you're not leaving the seeds for the birds, cut back your salvia plant to 1 or 2 inches above the soil after the frost kills them. You can also prune away any woody stems you find whenever you notice them.

Image Credit: sherjaca/iStock/GettyImages

How to Propagate Salvia

After flowering, the blossoms on the salvia plant drop seeds to resow themselves. Instead of letting the seeds fall where they like, you can collect and save them. Each tiny, trumpet-shaped flower holds a seed within it, so you'll need to pluck them from the plant and roll them between your thumb and forefinger to remove the chaff and claim the seed. Keep your seeds in a cool, dry place until planting season comes around again, and you can sow them.

You can also propagate salvia through cutting or division. Cut a nonflowering side stem off the plant that is about 4 inches long. Do this in late fall so you can root and overwinter your cutting inside to have a strong plant next spring.

Trim all the leaves from your cutting except the top two. After trimming your cuttings, fill a small pot with potting soil. With a knife to assist you, gently slide down the end of the cutting between the potting soil and the side of the pot. (For some reason, salvia cuttings tend to do better when placed there rather than in the center of the potting soil.) You can place several cuttings in the same pot.

Water your cuttings and place them where they will get lots of indirect sunlight. Keep them moist. A mist from a spray bottle a few times a day is perfect. After about three weeks, you can transfer your cuttings to their own pots and keep them going until spring.

Once your salvia plants are a few years old, you can dig them up and divide them if you want more plants. Do so in the early spring before the plant blooms. Simply make sure that each division has adequate roots and stems.

Common Pests and Other Problems for Salvia

Salvia has no particular insect pests of its own, but you may encounter the usual suspects: mites, aphids, thrips, snails and slugs. Snails and slugs are easy to pick off the plants by hand when you see them. You can knock other insect pests off the plant with a hose or apply neem oil or insecticidal soap to keep them at bay.

Although not caused by pests, flop is another problem sometimes encountered by salvia growers. Salvia plants should sprout strong, upright stems that are capable of supporting themselves and their flowers. Plants sometimes become floppy and top-heavy, however, and lie down on the job. Usually this happens when the plants have too much water, too much fertilizer or too little sun.

In the short term, you can stake floppy plants to keep them upright. Then, you should cut back on the water or fertilizer and see if you can restore the plant's own stiffness and vigor.

Common Diseases for Salvia

Salvia can suffer from Alternaria leaf spot and botrytis. Alternaria leaf spot appears as brown leaf spots with gray centers, while botrytis looks as though gray mold is growing on the plant. The best treatment for both is to pull affected plants and destroy them as soon as you notice a problem. Never compost diseased plants. Provide your plants with plenty of air circulation and don't play in the garden when your plants are wet.

Proper air circulation and gardening techniques can help avoid powdery mildew as well. Affected plants look as though they've been sprinkled in flour, but you can usually save afflicted plants with a fungicide application.

Root rot can become a problem as well and indicates that your soil isn't draining quickly enough. Remove the rotted plants, amend your soil with peat moss or sand and try again with new plants.

references

Home is where the heart is, and Michelle frequently pens articles about ways to keep yours looking great and feeling cozy. Whether you want help organizing your closet, picking a paint color or finishing drywall, Michelle has you covered. If she's not puttering in the house, you'll find her in the garden playing in the dirt. Her garden articles provide tips and insight that anyone can use to turn a brown thumb green. You'll find her work on Modern Mom, The Nest and eHow as well as sprinkled throughout your other online home decor and improvement favorites.

View Work