Fertilising guide

How to fertilise Tree Germander (Teucrium fruticans)— schedule & NPK

Also called Tree germander, Shrubby germander, Silver germander.

More about tree germander

About Tree Germander

Teucrium fruticans · also called Tree germander, Shrubby germander · herb

Teucrium fruticans is an evergreen, silver-leaved shrub native to the western Mediterranean — Portugal, Spain, southern France, and North Africa — where it colonises dry rocky slopes and garrigue. Its stems and undersides of leaves are densely white-felted, giving a striking year-round silver effect, while two-lipped pale lavender-blue flowers appear from spring through summer. The most important care fact is that it cannot tolerate prolonged freezing temperatures or waterlogged soil, so in colder gardens it must be given wall protection or overwintered under glass. Teucrium fruticans contains diterpenoids and should be treated as mildly toxic to pets.

Growth habit: Upright to spreading evergreen shrub with arching silver stems and opposite felted leaves.

What fertiliser tree germander actually wants — and why

Tree Germander is a soft, fast leafy herb that you harvest hard — a modest balanced feed keeps tender growth coming without tipping it into bland or bolting.

A balanced general feed (even N-P-K) at modest strength — enough nitrogen to keep replacing the leaves you pick, but not so much that flavour thins or it bolts to seed.

For the language behind the three numbers on the bottle — what nitrogen, phosphorus and potassium each do — see the NPK ratio explained entry. The short version for tree germander: match the feed to the job the plant is doing right now, not to a generic “plant food” on the shelf.

How often to feed tree germander, and which months

Feeding only earns its keep while the plant is in active growth and can use the nutrients — pour feed into a dormant or low-light plant and it simply builds up as root-burning salt. For tree germander:

Apply a low-nitrogen, balanced slow-release fertiliser sparingly in spring; excess feeding produces lush, soft growth that is more susceptible to frost damage. In practice: a balanced liquid feed every few weeks through the main growing and harvesting season (spring through early autumn), more often the harder you are picking it.

The dormant-season rule matters more than the exact interval: skip feeding entirely when tree germander is resting. For the wider context on indoor feeding rhythms across the seasons, the houseplant fertiliser schedule walks through the year month by month.

What strength to mix for tree germander

Half strength is a sensible default for tree germander — enough to fuel regrowth after cutting, gentle enough that the leaves stay aromatic rather than watery.

Feeding always goes onto already-damp soil, never dry roots — water tree germander first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the tree germander watering schedule.

Signs you are over-feeding tree germander

Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for tree germander:

Fast, soft, pale growth with diluted, less aromatic flavour.
Early bolting (running to flower) and a bitter edge.
Salt crust and scorched tips on container plants.

Signs you are under-feeding tree germander

Pale, slow regrowth after cutting and small leaves.
A tired, stalled plant that cannot keep up with harvesting.
Yellowing older leaves in a long-spent pot.

If the symptoms point at watering, light or roots rather than nutrition, the full tree germander care brief covers soil, humidity and the common problems for this species.

Flushing and leaching the salts

Pot-grown tree germander builds up feed salts quickly — water until it drains each time and flush the pot with plain water every few weeks, especially on a sunny windowsill.

Organic vs synthetic feeds for tree germander

Organic options

A diluted seaweed feed or worm-casting tea keeps soft growth coming without overdoing it. UK: dilute seaweed or Westland; US: Espoma Garden-tone or Neptune's Harvest. Gentle, hard to overdo, flavour-friendly.

Synthetic / liquid feeds

A balanced liquid feed at half strength through harvesting — UK: Phostrogen, Baby Bio or Westland; US: Miracle-Gro all-purpose at half strength. Fast regrowth; just do not overdo the nitrogen.

Brand names are examples, not endorsements, and UK and US ranges differ — check the label’s own NPK and dilution rate, since formulations change.

Fertilising tree germander — frequently asked questions

What fertiliser does tree germander need?

A balanced general feed (even N-P-K) at modest strength — enough nitrogen to keep replacing the leaves you pick, but not so much that flavour thins or it bolts to seed. Tree Germander is a soft, fast leafy herb that you harvest hard — a modest balanced feed keeps tender growth coming without tipping it into bland or bolting.

How often should I feed tree germander?

Apply a low-nitrogen, balanced slow-release fertiliser sparingly in spring; excess feeding produces lush, soft growth that is more susceptible to frost damage. Apply a low-nitrogen, balanced slow-release fertiliser sparingly in spring; excess feeding produces lush, soft growth that is more susceptible to frost damage. In practice: a balanced liquid feed every few weeks through the main growing and harvesting season (spring through early autumn), more often the harder you are picking it.

What strength of feed for tree germander?