Hosta 'Sum and Substance'

Sun

Partial shade; morning sun and afternoon shade usually give good leaf colour without scorching. Avoid hot afternoon sun, especially in warmer regions.

Water

Keep evenly moist during active growth, particularly while establishing and during dry spells. Avoid waterlogged soil.

Soil

Humus-rich, moisture-retentive but well-drained soil; tolerates acidic, neutral and mildly alkaline conditions.

Height

2-3 ft (0.6-0.9 m) in leaf; flower stems can reach 4 ft (1.2 m)

Spread

4-6 ft (1.2-1.8 m)

Flowers

Pale lavender, bell-shaped flowers on tall stems in mid- to late summer.

Foliage

Very large, thick, broadly heart-shaped leaves with prominent veins and a puckered surface; chartreuse to golden yellow depending on light.

Growth

Moderate; allow several years for a substantial mature clump.

Care needed

Low

• Pollinators
• Cold hardy
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Easy

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   1 ft (0.3 m)

2. After 1 year

   1.5 ft (0.45 m)

3. After 2 years

   2 ft (0.6 m)

4. After 3 years

   2.5 ft (0.75 m)

   full size

About 3 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Toxic

Growth rate

Moderate

• Water deeply during dry weather, directing water to the soil rather than repeatedly wetting the leaves.
• Spread compost around the clump in spring; use a balanced slow-release fertiliser only if growth is weak or soil is poor.
• Apply 2-3 in (5-8 cm) of organic mulch, keeping it clear of the crown.
• Protect emerging shoots from slugs and snails; thick mature leaves are more resistant, not immune.
• Leave established clumps undisturbed unless you need to divide or move them.

Pruning. Cut spent flower stems down to the base after flowering unless you want seed. Remove foliage once it has yellowed and collapsed in autumn, or clear it before new shoots emerge in spring.

Early spring

Clear old foliage before shoots emerge and check for slugs and snails.

Spring

Plant or divide as growth starts; water thoroughly and allow room for the mature spread.

Late spring

Top-dress with compost and renew mulch without burying the crown.

Summer

Water deeply in dry spells and watch for scorched leaf edges in exposed positions.

Late summer

Remove faded flower stems at the base.

Late autumn

Clear collapsed foliage and remove nearby debris that shelters slugs.

• Use a single mature clump as a focal point in a shaded border.
• Pair its broad golden leaves with fine-textured ferns and dark green foliage.
• Plant beside a shaded path or terrace, set back far enough that mature leaves do not obstruct access.
• Use in a sheltered courtyard in a very large container with reliable watering.
• Plant near a pond on moist, well-drained ground, not in standing water.

Garden styles it suits: Woodland, Japanese, Architectural minimal, Green on green, Modern courtyard and English country.

Plant it with: Japanese painted fern, Japanese forest grass, Siberian bugloss, Astilbe, Hellebores and Barrenwort.

Wildlife: Flowers attract bees and sometimes hummingbirds where these occur. The foliage is eaten by slugs, snails and deer; this cultivated hosta is not a native habitat plant in the United States, United Kingdom, Canada or Australia.

• Slugs and snails chew holes, especially in young leaves: inspect at dusk, remove them by hand and use labelled iron phosphate bait where needed.
• Deer browse foliage: protect plants with effective fencing where deer visit regularly.
• Leaf scorch causes brown edges or bleached patches: provide afternoon shade, maintain soil moisture and shelter from drying winds.
• Hosta virus X causes unusual mottling, streaking or puckering: there is no cure; remove infected plants, do not divide them, and disinfect cutting tools between plants.

Leaves, stems, flowers and roots contain saponins and are toxic to cats, dogs and horses if eaten, usually causing vomiting, diarrhoea or abdominal discomfort. Serious poisoning is uncommon, but contact a veterinarian after ingestion. Hostas are not generally considered poisonous to people, although eating this ornamental plant is not recommended.

• Hosta 'Empress Wu' (Hosta 'Empress Wu')

  Also forms a very large clump, but its mature leaves are dark green rather than chartreuse or gold.

• Hosta 'Sun Power' (Hosta 'Sun Power')

  Has golden foliage, but the leaves are narrower, more pointed and more strongly wavy than the broad leaves of 'Sum and Substance'.

Hosta honours the Austrian botanist Nicolaus Thomas Host.

Propagation. Divide established clumps in early spring as shoots emerge, keeping several buds and a good portion of roots on each division. Seedlings will not reliably retain the cultivar's characteristics.

Accepted botanical name

Hosta

Sources: GBIF (CC BY 4.0). The care and design notes are LandscapeGPT's own.