Start porterweed from a green stem cutting in warm weather. Stick it in water or in mix that drains. Seed is slower.
Take a stem cutting in warm weather
| Factor | Recommended | Avoid |
|---|---|---|
| When | Warm weather, from a soft green shoot | Do not take a brown woody stub, or wait until winter |
| Stem | A 4 to 6 inch tip with a few nodes; lower leaves stripped | Do not leave a flower spike as the only top |
| Rooting | A jar of water, or a draining mix kept just moist | Do not leave the water stale, or bury leafy nodes in wet peat |
| Warmth | Bright light out of hot midday sun | Do not set the jar on a cold, dark bench |
porterweed roots easily from a green stem. That is the usual home start, and it copies the parent. [1] Seed also works, but a cutting is faster. [2] Take a 4 to 6 inch tip in warm weather. Strip the lower leaves, and stand the bare stem in a jar of water with the remaining leaves above the rim. Change the water every few days. Roots often show in two to three weeks. You can also stick the same stem into mix that drains and keep it just moist. [3] A trailing stem that already sits on moist soil may root at a node. Leave it attached until the new roots hold, then cut it free. Easy plants still need the right kind: do not root a tall invasive lookalike and call it the native. [4]
- In warm weather, cut a 4 to 6 inch green tip just below a node. Strip the lower leaves.
- Stand the bare stem in clean water, or push it into a draining mix. Keep leaves above the waterline.
- Set it in bright light out of hot midday sun. Change jar water every few days, or keep the mix just moist.
- When roots are about 2 inches long, pot it on, then set it in sun after frost — see How to Grow Porterweed.
How do I start a new plant?
Take a 4 to 6 inch green stem in warm weather, strip the lower leaves, and root it in water or draining mix until roots take.
Seed is slower
Seed works if you already have it. Press the nutlets onto moist mix that drains, keep the tray warm, and do not let the surface dry out. A seedling is slower to flower than a cutting, so use a stem if you want a plant this season.
Can I grow porterweed from seed?
Yes, but it is slower. A stem cutting flowers sooner. Sow only if you already have seed and time.
Take a green tip, strip the lower leaves, and root it in water or draining mix. Pot it on when the roots hold.
FAQ
Do I need rooting hormone?
No. A fresh green stem in water or warm, draining mix still roots. Keep the water fresh, or the mix just moist.
What fails a cutting?
A woody stub, stale water, or a cold dark bench. Use a green shoot, change the water, and keep it warm and bright.
Related guides
Recommended plants
References
- [1] Florida Native Plant Society -
https://www.fnps.org/plant/stachytarpheta-jamaicensis - [2] Florida Wildflower Foundation -
https://www.flawildflowers.org/flower-friday-stachytarpheta-jamaicensis/ - [3] Houzz -
https://www.houzz.com/discussions/1960758/rooting-porter-weed - [4] Cape Coral Breeze -
https://www.capecoralbreeze.com/opinion/local-columns/2009/11/08/porterweed-shrubs-are-easy-to-grow-with-caution/
This note is part of Stachytarpheta Guides.
More notes on making another plant live in Propagating Guides.
Updated: Reviewed by Bosquelle Editors