Days to germination: 10 to 20 days, or start with cuttings
Days to harvest: 1 year for full harvest
Light requirements: Full sun
Water requirements: Occasionally during hot weather
Soil: Well-drained and light
You will want to look for the right kind of sage for an herb garden. For culinary uses, you should be growing common sage, garden sage or green sage. White sage is a different plant altogether and is not edible.
Sage is a perennial, so you can establish a bed of plants that will last for many years as long as your winters aren’t too cold. Zones 5 through 9 are the best for growing sage. While you could grow sage in colder areas as an annual, and let it die each winter, you will find that a single year doesn’t allow for enough growth to get a good harvest.
It grows a bit bigger than most other herbs, forming a shrub that is around 2 feet wide and up to 3 feet tall. There are a few varieties out there, some with variegated green leaves and some that are purple. Sage is an attractive plant that is often grown as an ornamental. The flowers are usually purple, and would look at home growing in your flower garden.
Starting from Seed
You can start your sage plants from seed but it germinates poorly, even with relatively fresh seeds. You will get a more reliable start if you go with cuttings or seedlings. If you know someone with a sage plant, cut stems will root very easily. Just prop up a fresh sprig in a glass of water until it sprouts roots. Then plant as you would any other seedling.
If you do want to try from seed, only plant them under about 1/8 of an inch of soil and keep moist until they sprout. It can take up to 3 weeks, so be patient. You can put the seeds out a few weeks before your last frost date.
Sage seedlings should be planted approximately 2 feet apart, in a location that will get sun all day long. Heavier soil is fine as long as there is still good drainage.
Dig the soil well before planting, sage grows best in loose soil. Add a dose of standard fertilizer or a bit of compost when you are planting to give your seedlings a good start.
Seedlings should go out in the garden around the time of your last frost, or slightly later.
Water your plants regularly for the first month or so, until they are well established. Then they should only need additional water during hot weather or a dry spell.
After your sage has flowered, prune it back a little bit to keep it from getting prematurely woody. You should be able to cut your plant down by almost a half after it’s bloomed. It will improve leaf production for the next season, increasing your herb harvest.
They shouldn’t need much for fertilizer through the year. One good feeding of compost or commercial fertilizer around mid-summer is helpful.
Sage grows well in a pot, but it may be too large for a window-sill garden indoors. They’ll need to be kept in full sun, whether inside or outside. You can keep a sage plant small by vigorous harvesting and regular pruning.
Pots for sage should have excellent drainage and you should only water the plants when the soil is dry. Choose a container that’s 8 inches across and around the same size in depth. You’ll only be able to grown one plant per pot.
Pests and Diseases
You will have to watch out for slugs in the sage patch. They can do serious damage to the leaves. Pick them off as you find them, or use commercial slug baits to control them. A less toxic method is to leave a shallow dish or saucer with beer near your plants. The slugs are attracted to it but then drown once they are in the dish.
Spittlebugs are also attracted to sage but are seldom a serious problem though they can make harvesting a little unpleasant with all their “spit”. They are small insects that make themselves a little home of foamy bubbles wherever they are feeding. Wash them off with a hard stream of water from the hose, and occasionally spray your plants with a natural insecticide. Products with pyrethrin is good for edible plants, though you don’t want to harvest any leaves right after spraying.
Sage does not do well with soggy roots, and your plants can suffer from root rot if they are watered too often or the soil doesn’t drain. Cut back on the watering if your plants are starting to go limp for no other apparent reason. Obviously, they may obviously also be wilting if there has been a long dry spell, so use your own judgment.
Harvest and Storage
To let your plant grow and get established, don’t harvest any leaves for the first year. Or at least harvest very lightly.
Like most leafy plants, you want to do all your harvesting before the plant goes to flower. The leaves will lose their aromatic qualities after that.
After about 4 years, your sage plants will start to get woody and will need to be replaced with new plants. Constant pruning and harvesting of the leafs can help prolong the life of your plants.
Drying is the most common way to store sage, though the taste will be reduced. Hang a bundle of fresh sprigs in a cool but ventilated area until they are completely dry. Then store in an airtight jar for up to a year. Fresh sage leaves will keep will in the fridge for 3 to 5 days, and you can also freeze it. Frozen sage will keep its flavor better than dried.
Sage can be a strongly flavored herb, so use sparingly until you are used to cooking with your home-grown herbs.