Russian sage, or Perovskia, is a late summer blooming perennial that bursts into flower like a cloud of blue. It goes from a hazy, pale blue to a jubilant azure. The long panicles of flowers become increasingly brilliant as they open. Russian sage is a woody subshrub. Although its branches are woody, like a shrub, the top portion of the plant may die back in cold winters. Since it blooms on new wood, Russian sage is often treated as a perennial plant.
- Foliage: Russian sage grows as a many stemmed clump. The foliage is finely cut gray-green leaves that are slightly scented.
- Flowers: Each stem ends with long, thin flower panicles. When fully in bloom it looks like a lavender-blue haze.
Russian sage is reliably hardy in USDA Hardiness Zones 4-9. Plants grown in Zone 4 may need some winter protection, but as long as the roots survive, your plants should send out new growth in the spring.
Mature Size of Russian Sage
Some varieties of Perovskia have a somewhat weeping form. They will start off growing tall and bend over under the weight of the flowers. Newer hybrids are sturdier and remain upright. Most will reach a mature size of 4 ft. (H) x 3 ft. (W).
Russian sage needs full sun to bloom well. Since it is drought tolerant, once it is established, it can handle dry, hot areas well.
Russian sage plants start blooming slowly, just hinting at their full color. The process tends to start sometime in July and continue through August. The flowers start off subdued and gain brilliance as they open, then gradually fade away again.
Russian Sage Growing Tips
You can start Russian sage from seed, but you will need to be patient.
Germination can take up to four months. In the meantime, you will need to keep the seeds continually moist and warm. Once they do germinate, it can be a few years before they are large enough to begin flowering. However, it is an option and a good way to get a lot of inexpensive plants.
Russian sage is usually grown from container plants. These can be planted any time during the growing season. If you are planting more than one, be sure to give each plant at least 2 - 3 ft. of space. They will quickly fill the space.
These plants are very easy to grow. They tolerate poor soil, drought, and a wide range of soil pH. Although Russian sage is extremely drought tolerant, new transplants will need regular water.
Caring for Russian Sage Plants
The biggest maintenance requirement of Russian sage is pruning. The flowers form on new wood -- branches that grew during the current season. In warmer regions, deadheading may result in a second flush of bloom. Otherwise, leave the flower heads for winter interest.
Gardeners in all climates should prune Russian sage plants back to about 6-8 inches in the spring. Do this just as the lower leaf buds are beginning to open, but before new growth fully starts.
Many varieties of Russian sage have a somewhat weeping habit. If you want a more upright plant either choose a variety bred to grow upright. like "Logi", or use something like pea brush to keep the weeping side from flopping.
Once established, the plants can start to spread by runners (it is in the mint family). They can become quite aggressive if you don't remove the new plants, roots and all, fairly soon. These offshoots do not transplant easily
It is recommended you divide plants every 4 - 6 years to rejuvenate them and to cut back on their ability to spread. Older plants do not divide well.
Garden Design With Russian Sage
This is an airy plant that makes a great specimen. The lavender-blue works especially well with whites and yellows and with other gray foliage plants.
Suggested Russian Varieties
- Perovskia "Filagran"’: has delicate, especially finely cut leaves
- Perovskia "Login": a narrower more upright plant than the species Perovskia atriplicifolia
- Perovskia "Little Spire": a dwarf variety that only gets about 2 ft. tall.