Seeds Irrigation 20 Seed (Lavandula × intermedia) Irrigation

Lavandula × intermedia, often called lavandin, is a vigorous hybrid lavender loved for its long, slender flower stems, silvery-green aromatic foliage and a bright, fresh, camphoraceous scent that is stronger and more penetrating than that of plain English types. The tall spikes hold their colour and fragrance beautifully when dried, making this variety a favourite for fragrant garden borders, low informal hedges, dried bouquets and scented sachets. Like all lavenders it is a Mediterranean plant that rewards full sun and lean, dry soil with abundant, bee-friendly summer bloom.

Planting

Direct seeding is not recommended for lavender. Start the seed indoors in flats or trays and transplant later — sowing about 8 to 10 weeks before the last spring frost. Sow about 3 mm deep in a soilless seed-starting mix; because lavender needs a little light to germinate, cover only very lightly, for example with a thin scatter of perlite. Keep the medium at roughly 18 to 21 degrees C, ideally over a heating mat, as bottom heat improves results. Germination is slow and uneven, usually beginning in about 14 to 21 days. Move seedlings into individual pots once they are big enough to handle, then plant them out in spring after the last frost. Set plants shallowly so the soil line sits just above the top roots, spacing them about 30 to 60 cm apart; allow 45 to 60 cm for full plants, or around 30 cm if you want a low hedge, with rows about 60 to 90 cm apart. Choose a spot in full sun — lavender will not thrive in shade. The soil must be light, well-drained and gravelly; lavender prefers poor, dry to moderately fertile, neutral-to-alkaline ground (pH roughly 6.5 to 8.3). Avoid heavy clay or waterlogged soil, and on heavy ground plant on a 20 to 30 cm mound or in a raised bed. In Egypt, start seed in trays in the cool autumn-to-winter window (about October to December) at 18 to 21 degrees C, then transplant out during the mild late-winter to early-spring period (about February to March), once the coldest nights have passed and well before the harsh summer. In the cooler, more humid Nile Delta with its heavier clay, plant on raised mounds or ridges 20 to 30 cm high or in raised beds with added grit, and use the wider 45 to 60 cm spacing for good airflow. In drier Upper Egypt the air suits lavender well, but make sure transplants are in and rooted before summer. Avoid summer sowing or transplanting anywhere in Egypt, and choose alkaline-tolerant types given Egypt's typically alkaline soils. Expect bloom in late spring and early summer.

Fertilizing

Lavender needs very little feeding — it actually prefers low-nutrient soil. A single application of slow-release fertiliser for the season is plenty, or instead work about 2.5 cm of compost in under the plants. In open ground no feeding is generally needed at all, so resist the urge to over-fertilise; lean soil produces tougher, more fragrant plants.

Care

After transplanting, give about 3.8 L of water per plant each week until the plants are established, watering newly planted lavender regularly through its first summer. Once established, lavender is very drought tolerant and only needs water during prolonged dry spells — avoid overwatering. Mature plants need only about 1.9 L every two weeks until flower buds form, then watering once or twice a week during flowering. In the Delta, water sparingly at the base, ideally by drip, to keep the crown dry. Prune annually in late summer after flowering: remove the spent flower stalks plus about 2.5 cm of leafy growth, but never cut back into the old bare woody stems, since lavender does not regenerate well from old wood. The main disease is Phytophthora root rot, caused by overwatering and wet or heavy soils, so ensure sharp drainage and avoid waterlogging. Pests are usually only a cosmetic concern and may include rosemary beetle, the sage or Ligurian leafhopper, cuckoo spit (spittlebug), and the bacterial pathogen Xylella; grasshoppers can reduce yields and deer may browse the plants.