Prostanthera 'Mint Royale'

Spring-Autumn · Indoors

Feed with houseplant food monthly

Give the plant a balanced houseplant feed monthly while in growth.

Where food elements are listed as three numeric values on the label representing in order Nitrogen(N)-Phosphorus(P)-Potassium(K), with percentage values for each, choose one where the values are more or less equal.

Spring-Autumn · Indoors

Water to keep the soil moist

Water moderately from the period when growth starts (around April) until the early autumn (September).

Spring - late · Outdoors

Feed with slow release fertiliser

Apply a general purpose slow release fertiliser, spreading it around the root area of the plant as it is coming into growth. (Or apply a liquid feed at regular intervals throughout the growing season.)

This is a simple way to provide a nutrient boost as a single annual procedure.

Spring-Autumn · Outdoors

Water to keep the soil moist

For best results, this plant needs soil that is always moist. Water deeply and regularly as soon as soil appears dry. Even for established plants in the ground, a dry week can cause problems with some soils. Check plants in pots more often, especially in hot weather. Or install an automatic irrigation system which will do the hard work for you, even when you are away on holiday.

Without regular watering some plants never fully regain their beauty.

Spring-Summer · Planting

Prune lightly after flowering

Give the plant a light haircut, generally tidying it up and removing any shoots that are wayward or damaged in any way. Dead flowers can be cut off if this is practical - the shrub may have too many, or they may be hard to reach.

Winter-Spring · Indoors

Water lightly in winter

The soil should remain just moist during the cold months when the plant is not in growth. Trickle a little water onto the soil surface every couple of weeks if the soil is dry. Do nothing if it is moist.

The roots remain active in winter and benefit from small amounts of moisture so they don't become completely desiccated.

Outdoor planting · Planting

Add root growth stimulant to the planting hole

Mycorrhizal fungi helps roots establish quickly, so they absorb water and nutrients more efficiently. It comes as a powder, granule or gel. Add to the planting hole or container, and to the plant's rootball before planting in the hole. For "bareroot" plants use a gel.

Compost · Planting

Loam based houseplant compost for repotting

Buy container or house plant compost that is loam based if possible (i.e. is based on John Innes compost number 2 or 3. This contains more fertiliser and is better suited to established plants.

John Innes no. 1 has the lowest level of fertiliser and is used for seedlings and young plants, so is generally used where plants will be 'potted on' after a number of weeks.

Indoor temperature · Planting

0C minimum temperature

This plant requires a minimum temperature of 0 Centigrade.

Indoor plant · Planting

Position in a sunny spot, close to window

Give this plant a position where there is as much light and sunlight as possible, within 2-3 metres of a sunny or bright window (one that is south, east, or west facing).