Sage is a shrubby, perennial evergreen plant which belongs to the family Lamiaceae.
It is grown for its aromatic leaves, which are used fresh or dry as a culinary herb. Oil can be extracted from the leaves and flowers of the plant and be used as a flavoring in alcoholic drinks and as a scent in perfume.
Sage can be erect or grow along the ground and has a dense arrangement of woody stems with broad, elliptical, silvery-green leaves which are arranged alternately on the stems.
The plant produces blue, pink or white flowers on a stalk, it can generally grow to 40–70 cm in height and can live for 15–20 years although they are usually replaced after 4–5 years in the garden when they become woody.
As the crop ages, it has a tendency to sprawl.
This herb grows best in warm, dry climates with full sunlight.
It thrives in a well-draining, rich, clay loams with an optimum pH of 5 – 7.5 and should be planted in full sun, although some afternoon shade is tolerated.
Sage plants require warm temperatures and ample sunlight in order to produce high essential oil content in the leaves.
The planting site should protected from wind.
Planting & Cultural Practices
Sage can be grown from seeds or cuttings.
Cuttings are however more preferred because seeds may take longer periods to produce harvestable plants.
If starting with seeds, they are first raised in a seedbed, where they take about 3 weeks to germinate and are then transplanted to the garden.
Seedlings are planted at a spacing of 25 – 30cm apart
Cuttings should also be planted at a spacing of about 25 – 30cm apart or more.
Rows should be spaced at 20-25cm apart.
Pruning– the oldest growth is cut out yearly and this helps in promoting new growth. It also helps to maintain an attractive shape of the plant.
Irrigation– the plant needs to be watered regularly during the first year to get established.
Mulching– plants need to be mulched after transplanting. This helps in moisture conservation and weed suppression. The decomposed mulch also releases nutrients into the soil.
Weeding– weeds compete with the plants for growth factors and this causes a direct effect on production. The garden should therefore be kept free from weeds.
Pests & Disease Control
Whiteflies– these are tiny and white flies and feed on the undersides of foliage by sucking the plant sap. They damage the sage plant by reducing vigor and leaves become malformed. They excrete excess sugar forming honeydew.
Spray TAURUS 500SP 10g/20l or PROFILE 440EC 30ml/20l or KINGCODE ELITE 50EC 10ml/20l
Thrips– these burrow deep into the sage plant’s flower buds and unfurled leaves, and may go undetected until the damage, which is shown as distorted, wilted buds and white-specked leaves, becomes evident.
Spray ALONZE 50EC 5ml/20l or PROFILE 440EC 30ml/20l or DEFENDER 25EC 40ml/20l
Aphids– these are usually white or green and are found clustered on tender new growth. They cause curling and distortion of foliar and excrete sugary substance (honeydew) which encourages the growth of sooty mold.
Spray KINGCODE ELITE 50EC 10ml/20l or LOYALTY 700WDG 5g/20l or LEXUS 247SC 8ml/20l
Crown gall– swellings/galls of various sizes develop on roots and root crown below the soil line and may occasionally grow on the stems. These galls are initially light colored bulges which grow larger and darken and may be soft and spongy or hard. If the swelling is severe and girdles the stem then plants may dry out and eventually die.
Drench soil with ALONZE 50EC 10ml/20l or mix fertilizer 50kg with ADVENTURE 0.5GR 2kg whenever doing basal application of fertilizer
Spider mites– infestation symptoms include white speckles on the leaves, especially near the large veins. Webs can be seen in cases of heavy infestation.
Spray ALONZE 50EC 5ml/20l or BAZOOKA 18EC 10ml/20l
Capsid bugs– these are sap-sucking pests that feed at the shoot tips, and on flower buds and can cause significant damages. Leaves near the shoot tips develop many small, brown-edged holes and may be misshapen.
Spray LOYALTY 700WDG 5g/20l or EMERALD 200SL 10ml/20l or LEXUS 247SC 8ml/20l
Rust– small, dusty, bright orange, yellow or brown pustules form on the undersides of leaves. New shoots may be pale and distorted, large areas of leaf tissue die and leaves may drop from plant in severe cases of infection.
Spray DUCASSE 250EC 20ml/20l or RANSOM 600WP 15g/20l or ABSOLUTE 275SC 10ml/20l
Bacterial Soft Rot – infection causes soft decay of the fleshy tissues, causing them to become slimy or watery. Shoots wilt and blacken at the base as infection continues.
Drench soil with GREENCOP 500WP 100g/20l or COLONIZER 440WP 100g/20l or TRINITY GOLD 425WP 100g/20l
Powdery mildew– white, powdery mold form on the upper surfaces of leaves and petioles. The foliage turns brown and wilt, then drop with heavy attack by the disease.
Spray DOMAIN 250EC 10ml/20l or RANSOM 600WP 15g/20l or BRADLEY 500SC 10ml/20l
Leaf spots– tiny, greenish yellow spots develop on the upper side of the leaves, which form white spots surrounded by a red band as infection progresses. These may drop out to give the appearance of shot-holes.
Spray RANSOM 600WDG 15g/20l or EXEMPO CURVE 250SC 15ml/20l or DOMAIN 250EC 10ml/20l
Root Rot – infection causes roots and underground stems to become rotted and yellowish brown to black. The outside layers of root slough off, leaving a central core.
Drench soil with PYRAMID 700WP 100g/20l or GEARLOCK TURBO 250WP 50g/20l or CHANCETYL ELITE 800WDG 100g/20l
Maturity, Harvest & Post-Harvest Handling
Sage requires 75-80 days from sowing to reach maturity, and is best harvested just before flowering when the essential oil content of the leaves is highest.
Sage should be harvested by cutting the top 20 cm of tender growth with a sharp knife. Commercial fields may be harvested by mowing but the highest quality product is achieved by harvesting only the leaves.
Leaves should be harvested sparingly during the first year of growth and normally in the following years. The leaves should only be harvested from the well-established plants.
The plants should be trimmed away 6-8 inches of leafy growth twice during the growing season in order to keep sage bushy.
Sage is best used fresh but may be stored.
To dry the leaves, snip them from the branches, and spread them on cloth or paper out of direct light in a cool, well-ventilated area. They may also be dried in a forced-air drier at temperatures below 125°F. When crispy dry, leaves are stored in an air tight jars, light-tight container.
Dried sage has a stronger and slightly different flavor than the fresh.
Sage can store for up to two weeks when dry leaves are loosely packed in plastic and stored in the refrigerator.
Sage leaves may also be frozen.
The optimum postharvest temperature and humidity are two degrees centigrade and 95-100% respectively.