Growing alstroemeria

Posted in All Gardening Advice, Perennials and Biennials, June, on

Growing Alstroemeria has sometimes been looked down upon in gardening circles, but I can't understand why.  Alstroemeria look lovely, are good value, and keep going long after more conventionally proper things have run out of steam.

See how Alstros grow by following Sarah in her garden last summer...

Choosing the best

To get the best, choose clear colours , not the dingy, half shades, that you so often see in their cellophane wraps as cut flowers.

There are various dwarf forms (the Little Miss series), where the proportion of flower to stem is all wrong and they look rather like a chubby little pony covered in rosettes.

Go instead for the 2ft-plus varieties. I also like the ones such as Alstroemeria 'Friendship', HRH Princess Alice and 'Adonis', where the individual flower stems are long once they branch at the top. This makes them more rangy and elegant and avoids any dumpy, over-stuffed feel.

How to grow

Plant alstroemerias in a sheltered site, in part shade or full sun, any time between May and August in good soil. All alstroemerias like good living, so give them plenty of organic matter at their roots. If watered regularly they will thrive; add a slow-release fertiliser in the spring.

All the taller forms need staking, or they will collapse in the wind or rain. Pick (or deadhead) them regularly and you'll get successional waves of flowers. The best way to do this is to pull each sten from near the base, like rhubarb. That leaves plenty of room for the next wave to come through which - in some varieties - grow taller than the previous generation.

Growing alstroemerias inside

If you have a greenhouse, alstroemerias are well worth growing inside, too. Pot them up into generous five-litre pots and keep them frost-free. Once they start to shoot in early spring, feed and water them well. You should then have flowers to pick from early May (earlier with extra heat), right through the summer into the autumn.

Cut flowers

Once cut, arrange them with a drop of bleach in their flower water (which should ideally be changed every four to five days), and they will then last three weeks in a vase. So let's all get over our taste bar on alstroemerias, and welcome them into our houses and gardens.

Why you should grow the newly-bred hybrid alstroemerias...

Growing alstroemerias from the newly bred hybrid types - developed by people such as the late James Smith with his Princess series, Parigo in Spalding and the breeding program of Mark Bridgen at the University of Connecticut - will give you magnificent plants. Like dahlias, these are tender tubers, growing alstroemeria has become much easier with our increasingly mild autumns and winters.

If you plant them deeply - with 4in-6in of soil on top of the tubers, so they're below the normal soil frost level - and mulch the clumps to protect them, most will reliably over-winter outside. Hardiness used to be a problem with some species and earlier-bred hybrids. They would start to shoot in April and would then be cut down by frost, which would knock them right back. But these modern early-flowering varieties such as 'Apollo' are made of sterner stuff. If frost cuts this one back, it just comes straight up again.

Unlike earlier hybrids, many of the recently bred varieties aren't three-week wonders either, the ones that flower only once in July, then die down, leaving you with a gap. The remarkable thing about many of the modern varieties is that they flower for months at a stretch, pumping out three or four separate flushes of flowers. And unlike the ligtu hybrids and some of the species (such as A. aurea), they don't seed everywhere and become invasive. After settling in for a couple of years, the new varieties spread slowly below ground, little by little, but not enough to become a pain - perfectly behaved, in fact.

We stock these new varieties of alstroemerias, sent out ready for planting straight away from April through to early summer. See our full range of alstroemeria plants.