Repotting guide

When & how to repot Shagbark manzanita (Arctostaphylos tomentosa)

Also called Shagbark manzanita, Woolly manzanita.

More about shagbark manzanita

About Shagbark manzanita

Arctostaphylos tomentosa · also called Shagbark manzanita, Woolly manzanita · flowering

Shagbark manzanita is a drought-tolerant California native shrub with shredding reddish-brown bark, woolly stems, and clusters of white to pale-pink urn-shaped flowers in late winter. It thrives in full sun, fast-draining acidic soil, and is highly fire-resistant once established. Ideal for Mediterranean-climate gardens with minimal irrigation.

Mature size: 1–3 m tall (3–10 ft), spreading 1–2 m wide depending on local conditions

Watch for — Root rot (Phytophthora): The most common and fatal problem. Caused by summer irrigation or heavy clay soils. Leaves yellow, then brown, and the plant rapidly collapses. Ensure excellent drainage and stop all summer watering once established.

How to tell shagbark manzanita needs repotting

Repotting on a calendar is less reliable than reading the plant. For shagbark manzanita, watch for these signs:

Roots spiralling thickly out of the drainage holes or pushing the whole plant up out of the pot.
The pot is so packed that water runs straight through in seconds and barely wets the soil.
It has split a plastic pot, or the rootball is a solid mass with almost no soil left when you slide it out.
Growth and (for shagbark manzanita) flowering have clearly stalled despite good light and feeding — but remember this plant likes being snug, so a little crowding alone is not a reason to repot.

For the underlying biology of a pot-bound root system and why it stalls a plant, see our guide to spotting and fixing a root-bound plant.

How often to repot shagbark manzanita

Only every 2–4 years, when genuinely crowded. Shagbark manzanita is one of the plants that genuinely prefers a snug pot — it grows and flowers better with its roots a little restricted, so resist the urge to repot it on schedule. Upright to spreading mounding shrub with distinctive peeling, shaggy bark on main stems.

What size pot to step shagbark manzanita up to

Go up only one pot size — roughly 2–3 cm (about an inch) wider in diameter, no more. Shagbark manzanita positively prefers a snug pot: it flowers and grows better when the roots are a little restricted. The single biggest repotting mistake here is over-potting — dropping shagbark manzanita into a pot two or three sizes up. All that surplus soil holds water the small root system cannot use, stays cold and wet, and rots the roots within weeks. When in doubt, choose the smaller pot.

Not sure of the exact diameter? Our pot size calculator takes the current pot and root spread and tells you the right next size — it deliberately recommends a single step up, never a big jump.

The best time of year to repot shagbark manzanita

Early spring, just as new growth restarts, is the ideal window for shagbark manzanita. The plant is moving into its strongest growth phase and re-roots into fresh soil quickly. Avoid repotting in winter dormancy or, for flowering plants, while it is in bud or bloom — recovery is slowest then and you risk dropping the flowers.

Step-by-step: repotting shagbark manzanita

Confirm it actually needs it. Slide shagbark manzanita out and check the roots. Only continue if it is genuinely packed — this plant prefers a snug pot, so if there is still soil and room, put it straight back.
Pick a pot only one size up. Choose a pot just 2–3 cm wider with good drainage. Resist anything bigger; over-potting is the main killer here.
Ease it out gently. Water lightly the day before, then tip shagbark manzanita out, supporting the base. Tease the outer roots free only enough to stop them circling.
Repot at the same depth. Add a layer of fresh sandy or gravelly, well-drained, acidic loam, set the plant so the soil line sits exactly where it did before, and backfill around the sides, firming lightly.
Settle it in. Water once to settle the soil, then let it sit. Hold off on more water until the top of the soil dries — fresh soil around a small root system stays wet for a while.

Aftercare

Because the new soil holds more water than the old crammed rootball did, ease right back on watering — let the top of the soil dry before you water shagbark manzanita again, or you will rot the roots in the very pot you just moved it to. Keep it out of harsh direct sun for a fortnight. Do not fertilise for about 4 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for shagbark manzanita

Shagbark manzanita wants sandy or gravelly, well-drained, acidic loam. Must have excellent drainage. Prefers slightly acidic soil (pH 5.5–6.5) low in nutrients. Heavy clay or organically rich soil causes root rot. Do not amend with compost or fertilizers at planting — leanness is key. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting shagbark manzanita — frequently asked questions

How often should you repot shagbark manzanita?

Only every 2–4 years, when genuinely crowded for shagbark manzanita. Only repot shagbark manzanita every 2–4 years, and only when it is genuinely root-bound — it flowers and grows best slightly crowded. Step up just one pot size in spring using sandy or gravelly, well-drained, acidic loam. The key mistake is over-potting: a too-big pot stays wet and rots the roots.

What size pot does shagbark manzanita need?

When is the best time of year to repot shagbark manzanita?

Does shagbark manzanita like to be root-bound?

Yes — shagbark manzanita genuinely flowers and grows best when slightly pot-bound, so do not rush to repot it. The mistake to avoid is over-potting into a much larger pot: the excess soil stays wet, the roots cannot use it, and the plant rots. Only repot every few years and only one snug size up.

Should you fertilise shagbark manzanita after repotting?

Not immediately. Wait about 4 weeks after repotting shagbark manzanita. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.