Gadenin日本語Get the appThree decisions before you plant
Most conebush failures trace back to soil and root handling. The plant evolved on lean, sandy, fast-draining ground in South Africa. Put it in a rich, moisture-holding potting mix and the roots can fail within months. Settle timing, mix and root handling first.
| Decision | Answer | Why |
|---|---|---|
| Timing | Early to mid spring, or early fall | Roots settle before heat or cold |
| Mix | Kanuma or pumice based, no fertilizer | Drainage, acidity and no phosphorus |
| Roots | Leave the root ball intact | Fine roots die when disturbed |
A lean, acidic mix: kanuma, pumice and peat
A proven recipe is five parts small-grade kanuma (a Japanese acidic volcanic grit), three parts pumice or perlite, and two parts peat or unlimed leaf mold, with no fertilizer added. If kanuma is unavailable, use a blueberry or azalea mix, which is acidic and low in phosphorus, and add 20 to 30 percent pumice for drainage.
Do not use general-purpose potting soil; it carries fertilizer and holds too much water. If you use a loam-based grit, choose a hard-fired type that will not break down and clog the pot.
- A deep layer of pumice at the bottom Fill the bottom 10 to 20 percent of the pot with coarse pumice so water clears the root zone quickly after heavy rain.
- Blend evenly, slightly moist Mix the parts thoroughly. Bone-dry peat repels water, so dampen it before blending.
- No fertilizer in the mix Leave out slow-release pellets, meals and manures. Avoid bagged mixes that list starter fertilizer on the label.
Choosing the pot
Go one or two sizes up from the nursery container: a 1 gal plant into a 10 to 12 in (25 to 30 cm) deep pot. Oversized pots stay wet too long. Terracotta or a plastic pot with large drainage holes both work; what matters is that the mix dries between waterings.
| Nursery size | Plant into | Next move |
|---|---|---|
| 4 in (10 cm) | 6 to 8 in (15 to 20 cm) | One to two years later, to 10 in (25 cm) |
| 1 gal | 10 to 12 in (25 to 30 cm) | Two to three years later, to 14 in (35 cm) |
| 2 to 3 gal | 14 to 16 in (35 to 40 cm) | Two to three years later, one size up, roots untouched |
Skip the saucer, or empty it after every watering. Raise the pot on feet so air moves under it.
Potting without breaking the root ball
Conebush roots are fine and brittle, and rot enters through damaged roots. Do not loosen the root ball, tease out circling roots or shake off old mix as you would with most shrubs. Slide it out of the nursery pot and set it in the new one exactly as it is.
- Water the day before A dry root ball crumbles when you pull it. Water the day before so it holds together, then squeeze the pot sides and ease the whole plant out.
- Set the height Add mix over the pumice layer until the top of the root ball sits 1 in (2 to 3 cm) below the rim. Planting deeper invites rot at the crown.
- Fill the gap Pour mix into the space around the root ball and settle it with a chopstick. Do not press hard; let water do the settling.
- Water through Water until it runs clear from the drainage holes to flush fine dust, then leave it alone until the surface dries.
- Rest in bright shade for a week or two Keep the new plant out of direct sun until new growth shows, then move it into full sun.
What happens after a fall planting
Planted in early fall, the shrub spends the rest of the season rooting and colors its bracts through the cold months. The temptation to feed a new plant is the most common mistake here. Carry it through the first winter with no fertilizer at all and consider a tiny low-phosphorus feed only once spring growth starts.
| Stage | What the plant is doing | Your job |
|---|---|---|
| Early fall | Rooting in | Bright shade, no fertilizer |
| Late fall to early winter | Bracts start to color | Full sun; under cover on frosty nights |
| Midwinter | Color at its deepest | Water only a few days after the mix dries |
| Early to mid spring | Color fades, new shoots | Prune after bloom; repot if needed |
| Late spring to early summer | Shoots extend | Move under cover before the rainy season |
If it sulks after planting: sort it out
Leaf drop or wilting tips a few weeks after planting point to damaged roots, wet mix or fertilizer. Lift the pot first: if it is still heavy and damp, stop watering. If the mix contained fertilizer, flush it. The one thing not to do is unpot and break up the root ball to inspect; that finishes off a weakened plant.
- Let it dry A wilted plant in wet mix is not thirsty. Move it to bright shade out of the rain and withhold water until the pot feels light.
- Flush out fertilizer If the mix had fertilizer, water heavily until it pours from the holes, and repeat two or three times a few days apart.
- Hands off until new growth Cut dead stems if you like, but do not lift the plant to look at roots. New shoots in spring mean it has recovered; until then, manage only light and water.