Wisteria Fertiliser

Transform Your Garden into a Personal Paradise!

Best Fertiliser for Wisteria

To get reliable spring blooms (not just masses of leaves), feed wisteria with a balanced, water-soluble fertiliser and keep nitrogen in check. The most practical single-bottle solution is CompleteGrow All Purpose Liquid NPK 20-20-20. It supplies even nutrition through the growth, bud-set, and recovery phases—without pushing runaway foliage.

Why this works:

  • Balanced NPK (20-20-20): Keeps growth, root health, and bud development in balance.
  • Water-soluble: Delivers nutrients right to the root zone; easy to dilute for pots or in-ground vines.
  • Flexible dosing: Use half-strength for “weakly, regularly” feeds that encourage flowers, not just vines.

Goal: Prevent excess nitrogen that fuels foliage at the expense of flowers; maintain steady phosphorus and potassium so buds form and open cleanly.

When to Fertilise Wisteria (Australia Month-by-Month)

Use CompleteGrow NPK 20-20-20 (liquid) all season, adjusting strength and frequency. Southern Hemisphere timing below.

Late Winter (Aug)

  • Objective: Wake roots; support early shoot growth.
  • Feed: 20-20-20 at half strength, once.

Early–Mid Spring (Sep–Oct)

  • Objective: Build buds; avoid foliage-only surge.
  • Feed: 20-20-20 at half strength every 3–4 weeks.

Late Spring–Early Summer (Nov–Dec)

  • Objective: Bloom support and post-flower recovery.
  • Feed: 20-20-20 at half strength once after main flowering flush.

Mid–Late Summer (Jan–Feb)

  • Objective: Maintain plant energy; set next year’s buds.
  • Feed: 20-20-20 at quarter to half strength if growth is active.

Autumn (Mar–May)

  • Objective: Wind down; avoid soft, sappy growth.
  • Feed: Generally skip unless plant looks nutrient-starved; if feeding, use very light dilution.

Winter (Jun–Jul)

  • Objective: Rest period.
  • Feed: No fertiliser. Prune structure; plan spring feed.

Climate note: Warmer zones (QLD/NT/Coastal NSW/WA north) often flower earlier; shift the schedule forward by ~2–4 weeks. Cooler zones (VIC/TAS/SA highlands) may run ~2 weeks later.

485128890_18014309168701100_7924007537602432838_n
491446140_674793161918989_6916085125107699157_n

How to Apply CompleteGrow 20-20-20

General rule: Always start at half the label rate for wisteria, then adjust based on response. Water the plant first, then feed—never fertilise bone-dry roots.

In-Ground Wisteria

  • Where to apply: Evenly around the dripline (the area under the outermost leaves), not right against the trunk.
  • How: Dilute liquid fertiliser in a watering can; apply to moist soil, then hose lightly to carry nutrients deeper.
  • Frequency: Follow the calendar (typically every 3–4 weeks during active growth).

Potted / Planter-Grown Wisteria

  • Dilution: Start at quarter to half strength—containers leach quickly but roots are confined and can burn.
  • Method: Feed until a little drains from the base; flush with plain water every 6–8 weeks to avoid salt build-up.
  • Frequency: Every 4–6 weeks in spring–summer if growth is active; pause in winter.

Soil & pH tips: Wisteria tolerates a range but performs best in slightly acidic to neutral soil (approx. pH 6.0–7.0). Compacted or waterlogged soils reduce nutrient uptake—improve drainage and mulch annually.

The Bloom Maximiser (Fertiliser + Pruning + Sun)

  • Full sun: Aim for at least 6 hours of direct light. Fertiliser can’t fix shade-starved buds.
  • Summer prune: After flowering, shorten long whippy shoots to 5–6 leaves to redirect energy to spur formation.
  • Winter prune: Cut those same spurs back to 2–3 buds—this is where flower clusters form.
  • Avoid lawn fertiliser drift: High-nitrogen lawn feeds nearby = leaves > flowers. Keep them separate.
  • Mulch smart: 5–7 cm of composted mulch (kept off the trunk) stabilises moisture and improves nutrient availability.

Troubleshooting: No Blooms, Pale Leaves, Salt Crust

SymptomLikely CauseFix
Lots of leaves, few/no flowersExcess nitrogen; shade; pruning off flower spursUse 20-20-20 at half strength; increase sun; prune summer/winter correctly
Pale or yellow leavesNutrient deficiency; poor drainage limiting uptakeResume light, regular feeds; improve soil aeration; mulch
White crust on soil surfaceFertiliser salt build-up (common in pots)Flush with plain water; reduce strength; feed less often
New growth blackened post-cold snapLate frost damageWait for regrowth; resume half-strength 20-20-20 when active
Young vine won’t flower (years)Immaturity; heavy nitrogen; shadePatience (seedlings may take 5–7+ yrs); light, balanced feeding; more sun
491440835_691092680033418_1284715596743849656_n
490576791_18063760598506297_6854046542199825242_n (1)

Wisteria Fertiliser FAQ

  • What fertiliser makes wisteria bloom? A balanced, water-soluble feed used lightly and regularly—CompleteGrow All Purpose Liquid NPK 20-20-20—supports bud formation without over-pushing foliage.
  • When does wisteria bloom in Australia? Typically late winter to mid-spring (Aug–Oct), earlier in warm zones and later in cooler regions.
  • How long do wisterias bloom? Usually 2–6 weeks depending on variety, climate, and whether late frosts hit the buds.
  • Can wisteria grow in pots? Yes—choose a very large, heavy pot, prune consistently, and feed lightly (quarter–half strength) every 4–6 weeks in the growing season.
  • Is wisteria deciduous? Yes. Leaves drop in winter; fertiliser resumes as growth begins in late winter/early spring.
  • Should I fertilise after flowering? Yes—apply one light recovery feed of 20-20-20 to rebuild energy reserves.
  • Can I over-fertilise? Definitely. If you see salt crust, random leaf burn, or “all vine, no bloom,” reduce strength/frequency and flush the soil.

Recommended Products

Sale!
Sale!

The Grow Blog: News, Tips, & Stories

Cart (0 items)

No products in the cart.