Hello, fellow garden enthusiasts! Today, we’re diving into the delightful world of propagating Hakea undulata, also known as the Wavy-Leaf Hakea. If you’ve ever admired its sculptural foliage and delicate flowers, you know how special this Australian native can be. Growing your own from cuttings or seeds is incredibly rewarding. Now, I’ll be honest, Hakea undulata can be a little bit of a finicky plant when you’re starting out, so it’s not always the easiest for absolute beginners. But with a bit of patience and the right approach, you’ll be well on your way to success!
The Best Time to Start
For the highest chance of success with Hakea undulata cuttings, I’ve found that early spring is absolutely the sweet spot. Think late March to April here in the Southern Hemisphere, or September to October in the North. The plant is just waking up from its winter rest, and the new, semi-hardwood growth is perfect. This is when the stems have enough energy but aren’t too soft and vulnerable.
Supplies You’ll Need
To get your Hakea propagation journey started, here’s a handy list of what you’ll want to have on hand:
- Sharp, clean pruning shears or secateurs: Essential for making clean cuts that reduce disease risk.
- Rooting hormone powder or gel: I swear by this for giving cuttings that extra boost. Look for one specifically for hardwood or semi-hardwood cuttings.
- A well-draining potting mix: A 50/50 blend of perlite and coarse sand or a commercial native plant potting mix is ideal. Avoid anything too rich.
- Small pots or seed trays with drainage holes: Clean is key here!
- A plastic bag or propagator lid: To create a humid environment.
- A spray bottle: For misting.
- Gravel or pebbles (optional): For the bottom of pots if you’re concerned about overwatering.
- A sharp knife or scalpel (optional): For preparing cuttings if needed.
Propagation Methods
While Hakea undulata can be grown from seed, it’s often quite slow and requires scarification (like nicking the seed coat or soaking in hot water) to even germinate. For a quicker and often more reliable path to new plants, I prefer stem cuttings.
Here’s how I do it:
- Take Your Cuttings: During the ideal propagation window, select healthy, non-flowering stems from a mature plant. Look for shoots that are firm but still have a little flexibility – this is your semi-hardwood. Take cuttings that are about 10-15 cm long. Using your clean secateurs, make a clean cut just below a leaf node (where a leaf attaches to the stem).
- Prepare the Cuttings: Gently remove the lower leaves from your cutting, leaving just 2-3 at the very top. If the leaves are very large, you can even trim them in half to reduce water loss through transpiration. If you’re using a knife, you can lightly scrape a thin sliver of bark from one side of the base of the stem, about 2 cm long. This can sometimes encourage rooting.
- Apply Rooting Hormone: Dip the cut end of each cutting into your rooting hormone. Tap off any excess – you just want a light coating.
- Plant Your Cuttings: Fill your clean pots or trays with your well-draining mix. Make a hole in the centre of the mix with a pencil or your finger. Insert the cutting into the hole, ensuring the bottom leaf nodes are just touching the soil. Gently firm the soil around the cutting.
- Create Humidity: Water the soil gently until it’s moist but not soggy. Then, cover the pot or tray with a clear plastic bag or a propagator lid. This will create a greenhouse effect, keeping the humidity high, which is crucial for cuttings to root before they can take up water from the soil.
The “Secret Sauce” (Pro Tips)
Here are a few tricks I’ve learned over the years that can really make a difference:
- Hygiene is King: I cannot stress this enough! Sterilise your secateurs and pots before you begin. A quick wipe with isopropyl alcohol or even a bleach solution followed by a good rinse works wonders. This sad truth is that most cuttings fail due to fungal infections, not lack of rooting.
- Bottom Heat Helps! If you have the option, placing your propagator on a gentle heat mat can significantly speed up the rooting process. The warmth encourages root development from the base of the cutting. Just a “warm to the touch” temperature is all you need.
- Don’t Let Leaves Touch Water: If you’re attempting water propagation (which is less reliable for Hakea but some try it), ensure that no leaves are submerged. Only the stem should be in the water. Leaves in water will rot and can spread that rot to the cutting.
Aftercare & Troubleshooting
Once your cuttings are planted, the waiting game begins! Keep them in a bright spot, but out of direct scorching sun. Mist the leaves occasionally if the humidity inside the bag seems to be dropping.
Be patient! It can take anywhere from 4-12 weeks, sometimes even longer for Hakea undulata, before you see signs of rooting. You’ll know they’re rooting when you see new leafy growth appearing at the top. You can also give a very gentle tug – if there’s resistance, roots are forming.
If your cuttings turn yellow and mushy, or if you see black spots developing, it’s likely due to overwatering and a fungal infection. Too much moisture is the enemy. Ease up on watering and ensure good air circulation when you eventually remove the lid. If a cutting looks completely dead, it’s best to discard it to prevent any potential spread of disease to your other cuttings.
Happy Propagating!
Don’t be discouraged if your first few attempts aren’t perfect. Gardening is a journey of learning and observation. The key with Hakea undulata is to give it that warm, humid environment and well-draining conditions. Enjoy the process of nurturing these new little plants – there’s nothing quite like watching them grow roots and eventually become beautiful specimens in their own right. Happy propagating!
Resource:
https://identify.plantnet.org/k-world-flora/species/Hakea%20undulata%20R.Br./data