How to Grow Antirrhinum
'Night & Day' from Seed
Velvet crimson snapdragons with a sharp white throat, over bronze-green leaves. A spicy scent, edible flowers and colour that deepens as the autumn nights turn cold.
'Night & Day' takes the near-black crimson of the old heirloom 'Black Prince' and sets a bright white lip against it. The contrast is striking up close, and the bronze-green foliage behind the spikes makes the whole plant look richer than a plain green-leaved snapdragon.
It is one of the few annuals that looks better at the end of the season. As nights cool in September, the red darkens towards black and the leaves turn burgundy, just as most of the border is fading. It also has a spicy scent, which is unusual for a snapdragon.
Quick Facts at a Glance
Plant Type
Half-hardy annual
Sowing Time
Feb to Apr · Sep to Oct, under cover
Flowering
June to September
Position
Full sun
Height
Around 45cm
Difficulty
2 out of 5, easy
Understanding the Plant
'Night & Day' is a variety of Antirrhinum majus descended from 'Black Prince'. Like all snapdragons it is a short-lived perennial grown here as a half-hardy annual. Each spike carries deep crimson flowers with a white throat, and the colour holds its contrast in both sun and shade.
The flowers are edible and can be used on salads or floated in drinks. Bumblebees visit them constantly. In a vase they last around five to seven days, a little less than modern double snapdragons, so treat them as a flower to cut for the week.
A flower for autumn
Cold nights in September deepen the crimson and turn the foliage burgundy, so the white lip stands out even more sharply. If you plan borders for late colour, this is a snapdragon worth placing where you will see it in autumn.
When & How to Sow
The seed is very fine and needs light to germinate. Sow under cover from February to April for summer flowers, or in September and October for stronger, earlier plants the following year.
Autumn-sown plants
Plants sown in September or October need a frost-free greenhouse, cold frame or cool porch over winter. Keep them on the dry side, then plant out in April or May. They flower earlier and on bushier plants than spring sowings.
Sow on the surface. Sprinkle the seed thinly over fine, damp seed compost and press it in without covering. Keep at around 18 to 21°C under a clear lid. Seedlings appear in 10 to 21 days.
Prick out and grow on cool. Move seedlings into modules once they have true leaves, and keep them bright and cool so they stay short and sturdy.
Pinch, harden off and plant out. Nip out the growing tip at four or five pairs of leaves. Harden off and plant out in April or May once frosts have passed, 25 to 30cm apart.
Growing On Tips
Full sun
Plant in full sun and well-drained soil for sturdy spikes and the richest colour.
Plant in fives or sevens
Dark flowers absorb light, and a single plant vanishes against soil. Groups make an impact.
Cutting
Cut when the lowest third of the spike is open. Expect five to seven days in the vase.
Deadheading
Cut spent spikes back to a pair of leaves to bring on side shoots and more flowers.
Edible flowers
Pick individual flowers for salads, cakes or drinks. The white throat makes them a striking garnish.
Keep leaves dry
Water at the base in dry spells. Wet leaves encourage rust.
Common Problems & How to Fix Them
| Problem | Likely Cause | What to Do |
|---|---|---|
| Orange-brown spots under leaves | Antirrhinum rust | Remove affected leaves and pull badly affected plants. Water at the base, space plants well and rotate where you grow snapdragons. |
| Seedlings collapse at soil level | Damping off | Use clean trays and fresh compost, water from below and keep air moving once seedlings emerge. |
| Tall, weak seedlings | Too warm or too little light | Grow seedlings on in the brightest, coolest spot available after germination. |
| Autumn-sown plants rot over winter | Cold, wet compost | Water sparingly from October to February and keep plants in a well-ventilated frame or greenhouse. |
| Short vase life | Typical of this variety | Cut in the cool of the morning, strip lower leaves and change the water every couple of days. |
When to Expect Flowers
Autumn-sown plants usually flower from early June, and spring sowings from late June or July. With regular cutting, flowering continues through September, when the colour is at its darkest.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 🌱 Sow under cover | ||||||||||||
| 🪴 Plant out | ||||||||||||
| 🌸 Flowering |
Plant Specifications
Crimson and white snapdragons that finish the season strong
Sow under cover in spring or autumn, plant out in groups after the frosts, and enjoy spicy-scented spikes that get darker as the nights cool.
Shop Antirrhinum Night & Day Seeds →