🌿 Snapdragon

Grow snapdragons in fertile, well-drained soil (preferably potting soil) enriched with organic matter/compost to retain moisture without clogging. Avoid heavy, poorly drained clay soils; raised beds or the addition of gravel can improve drainage. Best performance is obtained in neutral to slightly alkaline soils (approx. pH 6.2-7.5). Keep soil evenly moist but not saturated.

Sow indoors in seed trays or pots 6-8 weeks before the last expected frost. Snapdragon seeds need light to germinate, so press them into the medium and cover only lightly (if at all) with fine vermiculite. Store at 18-21°C (64-70°F) in full sunlight and maintain regular humidity (misting or deep watering; avoid waterlogging). Germination generally takes 10-14(-21) days. When seedlings have several true leaves, transplant or pot them, keeping them in a cool, well-lit place to prevent stretching. Harden them off gradually, then transplant them outdoors once the risk of hard frost has passed. Plant in fertile, well-drained soil, in full sun or light shade; space about 20-30 cm apart, depending on variety. Water well and maintain regular humidity until the plant is established. In mild-winter climates, seeds can also be sown in the open ground in early spring, when the soil is workable, or in late summer or early autumn, to overwinter and flower earlier the following spring.

Snapdragons (Antirrhinum majus) feed lightly to moderately; too much nitrogen will cause leaf growth and flower decline. Before planting, incorporate compost or a small quantity of a balanced, slow-release fertilizer into the bed at the rates indicated on the label. During the active growth period, feed sparingly: if the soil is average, apply a balanced fertilizer (e.g. 5-5-5 to 10-10-10) as a light lateral or liquid spread about every 4 to 6 weeks, or only when growth is pale or slow. In containers, use a diluted, balanced liquid fertilizer every 2 to 3 weeks, as nutrients are leached out more quickly. Avoid high-nitrogen lawn fertilizers, and stop applying large quantities of fertilizer when flowering is strong or at the end of the season. Adjust fertilizers according to soil analysis, if necessary.

Apply a light organic mulch (compost, leaf mold, fine bark) to a depth of around 2-5 cm after planting to conserve moisture and suppress weeds. Keep the mulch a few centimetres from the stems and crown to reduce the risk of rotting, especially in cool or damp conditions; snapdragons prefer good drainage and air circulation at the base. In colder regions, a slightly thicker winter mulch can be added after the onset of frost to protect the roots, then removed in spring.

Tall snapdragon cultivars (Antirrhinum majus) should be staked to prevent lodging from wind and rain. Insert supports at planting time to avoid disturbing the roots: use slender bamboo canes or branched pea sticks, or stretch horizontal flower net/supports over the bed when the plant is grown in rows. Tie stems as they elongate with flexible ties (string, fabric strips or plant clips) in loose figure-of-eight loops, spacing ties every 20-30 cm (8-12 in) on very tall tips. In exposed sites, use several canes with a circular corral/twine around a clump, or grow in dense groups for mutual support; avoid tight ties that shrink stems.

Deadhead regularly by cutting off spent flower spikes just above a leaf node to encourage continued flowering. Pinch out young plants (remove the tip of the plant when it has reached a height of 4-6 in/10-15 cm) to encourage branching and a bushier habit. After main flowering, shear or cut back plants by about a third to a half to stimulate new growth and a second flowering, especially in cool weather. Quickly remove weak, damaged or diseased stems; in mild-winter regions where plants overwinter, cut back heavily in late winter or early spring to refresh growth.