Aster 'Wood's Purple'

Questions about aster 'Wood's Purple'

Does aster 'Wood's Purple' need sun or shade?

Aster 'Wood's Purple' grows in full sun (6 or more hours of direct sun a day).

It wants ordinary well-drained soil, of average fertility, and a good soak in dry spells.

What zones does aster 'Wood's Purple' grow in?

USDA zones 4 to 8. It is hardy to zone 4, which means it survives winter nights down to about −20 °F (−29 °C).

Above zone 8 it struggles: the zones measure winter cold, but a plant's top zone usually means the summers are too hot or the winters too mild for it to rest.

Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.

When does aster 'Wood's Purple' flower in my zone?

In zone 5 it flowers early September to mid October. As an autumn flower it keeps much the same dates in every zone: it answers to shortening days and cool nights more than to the warmth of spring.

Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.

How far apart should aster 'Wood's Purple' be planted?

16 in (40 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 18 in (45 cm), so a group knits into one patch.

It grows 16 in (40 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.

How many aster 'Wood's Purple' plants do I need?

At 16 in apart, set out in staggered rows:

• 7 to fill 10 square feet (about 1 m²)
• 8 for a single row 10 ft (3 m) long
• 21 to fill a 4 × 8 ft bed on its own

In a mixed border, plant it as runs of three or five along the front (or one even row, in a formal bed).

In the bed above, the planner used three in one group.

Is there a native plant like aster 'Wood's Purple'?

Aster 'Wood's Purple' is not native to North America. These North American natives come closest to doing its job:

• Scarlet coral bells: the same job in a bed and the same size; flowers late May to late July, red, pink or white, not purple.
• Alpine aster: the same job in a bed and the same colour; 6 in shorter, 4 in narrower.

Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.

What flowers after aster 'Wood's Purple'?

Aster 'Wood's Purple' is over by mid October. These start as it finishes and carry the same spot on, so it never goes flat:

• Japanese onion 'Ozawa': from early October to early November, 10 in tall, to stand in front of it and cover its fading stems.
• Tatarian aster 'Jindai': from early October to early November, 4 ft tall.
• Bodnant viburnum 'Dawn': from early November to late December, 10 ft tall.

What does aster 'Wood's Purple' look like in winter?

Aster 'Wood's Purple' dies down to the ground and there is nothing to see until spring. The old stems can be cut in autumn, or left until spring as shelter for overwintering insects.