How to protect Peruvian lilies in winter?

Variable hardiness

If successive hybridizations have produced varieties of Alstroemeria particularly well adapted to growing in open ground under most of our climates, some Alstroemeria can suffer in regions with harsher winters. Among the many varieties, the following can be distinguished :

• Alstroemeria that tolerate down to -15°C. More hardy, they can be grown in our cold climates if soil does not remain waterlogged in winter and provided they are protected by a thick mulch. High-altitude Alstroemeria native to the Chilean Andes and Patagonia are the hardiest, such as Alstroemeria aurea (syn. aurantiaca). Alstroemeria ‘Mauve Majesty’ is part of a series of hybrids selected in the United States for their exceptional hardiness: it can withstand our typical winters, with or without protective mulch, when grown in well-drained soil. Hybrids of species A. ligtu and hybrids of the line called ‘Summer Paradise’ are also notable for their hardiness.

• Inticancha® series Alstroemerias prove to be perennials of low hardiness, easier to grow as annuals in flowering containers. Growing them in open ground should be reserved for very mild coastal or Mediterranean climates. Elsewhere, grow them in pots in full sun and overwinter in shelter to preserve them.

Note : Generally, these plants are vulnerable to severe cold. In cold regions, a thick mulch of leaves, dry turf or fern fronds, applied in autumn, helps alstroemerias better withstand cold.

How to protect Alstroemeria (Peruvian lily) from the cold?

Inca lilies in open ground

On the coast and in regions with mild winters, your Inca lilies can remain in the ground. Although there are fairly hardy varieties able to withstand down to -8°/-15°C in very well-drained soil, Alstroemeria planted in the garden need good winter protection.

In autumn, cut back foliage to ground level and protect the stump with a mulch 10 to 25 cm thick of dead leaves, straw or fronds of ferns: this blanket bog insulates the roots from cold. Foliage will disappear completely in winter but plants will regrow vigorously in spring.

→ To learn more and to grow them successfully, feel free to consult our factsheet: “LYS DES INCAS, ALSTROEMÈRE : PLANTER, CULTIVER, ENTRETENIR”

Inca lilies grown in pots

In colder regions, growing Inca lilies in pots allows sheltering less hardy plants from frost, keeping them safe and bringing them out again in the growing season.

Bring pots in at first frosts and shelter them frost-free in a bright, airy and lightly heated space (conservatory or greenhouse) where temperature will always remain above 0°C.

Mulch the surface to a good thickness and keep soil slightly moist: remove saucers to avoid stagnant moisture around roots. Ensure substrate is neither waterlogged nor dry.

Put pots back outside after last frosts. In spring, apply a liquid fertiliser to encourage regrowth.

If you cannot bring pots in for winter; wrap pots with several insulating layers of cardboard, newspaper or bubble wrap, secured with string. Place containers near a wall, sheltered from cold winds. Remember to remove this protection as soon as temperatures warm up.

→ We offer our wide range of Alstroemeria or Inca lilies, where you will find varieties best suited to your climate.