Mature size & growth rate

How big does MacGillivray's Wax Plant (Hoya macgillivrayi) get?

Also called MacGillivray's wax plant, Red hoya, MacGillivray's hoya.

More about macgillivray's wax plant

About MacGillivray's Wax Plant

Hoya macgillivrayi · also called MacGillivray's wax plant, Red hoya · tropical

Hoya macgillivrayi is a fast-growing, twining climber endemic to the Iron Range and McIlwraith Range of Cape York Peninsula, Queensland, Australia, where it scrambles through rainforest at the forest edge. It produces some of the largest flowers in the genus — up to 6 cm across — in rich burgundy red, with a glorious citrus-and-gardenia fragrance that can last up to three weeks; the most important care tip is to keep it slightly pot-bound and reduce watering in winter to encourage prolific flowering. The ASPCA lists the Hoya genus as non-toxic to cats and dogs.

Mature size: Can reach 3–5 m or more outdoors in tropical climates; typically 1.5–2.5 m as a container or greenhouse plant.

Indoor size vs how big it gets in the wild

MacGillivray's Wax Plant does not get tall — it gets long. Size here is about stem length and how you train or cut it, not how much floor it claims. Indoors and in a pot, expect can reach 3–5 m or more outdoors in tropical climates. In the ground with no restriction it is a completely different plant — typically 1.5–2.5 m as a container or greenhouse plant. — which is why the pot, the light and the pruning matter so much for the size you actually end up with.

Growth shows up as lengthening stems that trail down or climb up a support; the plant can be kept tiny or grown metres long from the exact same root system.

Growth rate and years to mature

MacGillivray's Wax Plant is a fast grower. Realistically, expect one to three growing seasons — fast vines can add a metre or more of stem in a single good summer. Its feeding profile backs this up: apply a slow-release fertiliser at nine-monthly intervals or a dilute liquid feed (low nitrogen, higher phosphorus) every six to eight weeks during the growing season; overfeeding reduces flowering.

Want this turned into the right next pot at the right moment? The pot size calculator and the macgillivray's wax plant repotting guide cover when and how much to size up — pot size is one of the biggest levers on how fast macgillivray's wax plant grows.

How to keep macgillivray's wax plant smaller

You are not stuck with the maximum size. For macgillivray's wax plant specifically, these are the levers, in order of impact:

Trim the longest vines back to the length you want — macgillivray's wax plant takes hard cutting well and bushes out from the cut.
Cut just above a leaf node; each trimmed stem usually branches into two, so pruning makes it fuller, not sparser.
The cuttings root easily in water or mix, so "keeping it smaller" doubles as free new plants.
Expect to tidy it every few weeks in summer — this is a fast vine that will sprawl if left.

The keep-it-smaller method, step by step

Decide the length you want. Pick the point each vine of macgillivray's wax plant should stop — you can be aggressive; it regrows readily.
Cut just above a node. Snip about 0.5 cm above a leaf node so the stem branches there instead of dying back.
Root the cuttings. Drop the trimmed pieces in water or mix — they root in 2-4 weeks and can fill the same pot for a bushier look.
Repeat as it runs. Re-trim whenever it overshoots; regular light pruning keeps it both smaller and fuller.

How to grow macgillivray's wax plant bigger or faster

If you want it to fill the space sooner, push the conditions rather than hoping — for macgillivray's wax plant the accelerators are:

Good light plus a moss pole or trellis triggers the longest, fastest, largest-leaved growth.
Give it something to climb — many vines grow far faster and bigger up a support than trailing.
Feed through spring and summer and keep it consistently watered while it is actively running.

Light is almost always the ceiling. The macgillivray's wax plant light requirements page covers exactly how bright a spot it needs to grow at its potential instead of stalling.

When macgillivray's wax plant outgrows the room (or the pot)

"Too big" usually arrives as one of these signs for macgillivray's wax plant:

Vines pooling on the floor or wrapping past where you want them — purely a trimming cue, not a repot one.
Bare, leggy stems with leaves only at the tips (usually a light problem, not a size one).
A tangled mass that has outrun its support and needs cutting back and re-training.

If it is the pot rather than the room, it is a repotting job, not a goodbye — see the macgillivray's wax plant repotting guide. If you want more of this plant instead of a bigger one, the macgillivray's wax plant propagation guide turns prunings into new plants.

MacGillivray's Wax Plant size — frequently asked questions

How big does macgillivray's wax plant get?

MacGillivray's Wax Plant reaches can reach 3–5 m or more outdoors in tropical climates when grown indoors, and far larger where it grows unrestricted (typically 1.5–2.5 m as a container or greenhouse plant.). Growth shows up as lengthening stems that trail down or climb up a support; the plant can be kept tiny or grown metres long from the exact same root system.

Is macgillivray's wax plant slow or fast growing?

MacGillivray's Wax Plant is a fast grower. Expect one to three growing seasons — fast vines can add a metre or more of stem in a single good summer. MacGillivray's Wax Plant does not get tall — it gets long. Size here is about stem length and how you train or cut it, not how much floor it claims.

How long does macgillivray's wax plant take to reach full size?

Roughly one to three growing seasons — fast vines can add a metre or more of stem in a single good summer. Light, pot size and feeding move that timeline more than anything else.

How do I keep macgillivray's wax plant smaller?

Trim the longest vines back to the length you want — macgillivray's wax plant takes hard cutting well and bushes out from the cut. Cut just above a leaf node; each trimmed stem usually branches into two, so pruning makes it fuller, not sparser. The cuttings root easily in water or mix, so "keeping it smaller" doubles as free new plants. Expect to tidy it every few weeks in summer — this is a fast vine that will sprawl if left.

How can I make macgillivray's wax plant grow bigger or faster?

Good light plus a moss pole or trellis triggers the longest, fastest, largest-leaved growth. Give it something to climb — many vines grow far faster and bigger up a support than trailing. Feed through spring and summer and keep it consistently watered while it is actively running.