How to grow alstroemeria

These florist-type Alstroemeria have an extraordinarily long flowering period in the herbaceous border

Please excuse the pretentious title but confident titles attractive search engine attention. My knowledge is little more than the average gardener but I like to pass on my own experience of growing. I feel many articles about plants are written by people who have never grown them, who have an axe to grind and trawled the literature to compose their pieces often written with absurd generalisations and dubious facts. 

Even the RHS when I did a little browsing myself tells you to feed your alstroemerias weekly. Well really, I hardly ever feed mine except perhaps during propagation or to get a new plant going when it might get a light top dressing of a general fertiliser such as Yaramila.

This yellow florist type alstroemeria has proved particularly hardy and reliable

Why are alstroemeria not more widely grown?

Writer Bunny Guinness, says alstroemeria are one of gardening’s best kept secrets! So many varieties are easy to grow, make sturdy long flowering plants of a quality for cutting every bit as good or better than the very same kinds expensively glasshouse grown and bought at the florist.

They require little staking. None at all in my own borders where I grow them in bold clumps. They are tolerant of most soil types albeit those short of extreme wetness. My own are in full sun for at least part of the day or in very light dappled shade. A particularly useful feature is that once established their deep tuberous roots enable survival in very dry places

What can go wrong? 

This dark florist type is only subtly different from my first illustration

There is quite a variability in hardiness. Some are bone hardy and mine survived minus 20 centigrade in the double Winter of 2010 (A long cold January and February, followed in the same year by a vile November and December). Other varieties are less hardy and may subside at minus single centigrade figures, especially in their first Winter. Because I am so careless at remembering my plant names I shall have today to guess the identity of the successful varieties in my own gardenI have found the varieties of alstroemeria that do well for me by a process of natural selection. Those bought at the garden centre have either lived or died. This is not a fair measure of a varieties suitability. The cynic in me says that many garden centre plants however good a variety are destined to die. Grown soft, overfed in polytunnels, sprayed temporarily clean with professional fungicides they succumb within the year of purchase and the poor gardener blames his own incompetence. And that's not to mention repeated distress on a garden centre bench.

They can be rather aggressive

Alstroemerias have a reputation to ‘run’ and spread vigorously. To me that is a very good thing! I have no problem of containing them at all and if they fill their space to make a strong clump this is ideal. I find routine garden maintenance practice quite sufficient to retain them. Should they really go mad for those at a distance a glyphosate spray will stop them in their tracks without damage to the parent clump! Best in Spring before anyone should notice. More cautious  gardeners might just spade them back.

Auntie Margaret’s alstroemeria. A warning!

It was a very startling orange one

For several years we would make our three monthly visit to Huddersfield to see my widowed auntie and to do her more difficult gardening chores.

I don’t remember whether I planted her half metre clump of a rather distinct orange alstroemeria or whether it was there all the time.

It became apparent - she made it very clear - she did not like it and asked me to remove it. Some say I am stubborn, I was certainly tardy and failed to comply. 

She secretly asked her jobbing gardener to dig it out. I never noticed as it always grew back. It has very deep roots and her man was merely propagating it. 

Eventually she instructed me to get rid. Reluctantly I sprayed the whole plant with glyphosate and it was gone.

Brenda agreed with Margaret and declared  “about time”

Varieties

This weak growing variegated one needs special attention

There are many species of alstroemeria although most are not grown in the UK. It seems to me that for most gardening purposes they fall into two types. For my pictures I call them type1 or 2

Type 1 Once a year flowering and always yellow through to orange.

The once flowering kind

This kind completely dies down in Winter and flowers only once Mid June /July. Flowers might last a month if you are lucky but look rather nice - if you like orange! It often sets seed but only in unruly gardens where this annoying habit might be a good thing! Varieties’ colour reflect their easy hybridisation and their colour pallet is usually a spectrum of red to orange. They are reliably hardy as Auntie Margaret found.

Type 2  Often evergreen, hybrid florist varieties

They flower six months  and soon fill the space when my Corydalis elatum dies down

Selections from those bred for flower production are the very best kind. They flower from May right through the Summer into late Autumn on sturdy stems with a fantastic range of multicoloured flowers.You need to cut out complete stems when they ‘go over’ to enhance complete continuity.

Don’t be fooled by the word ‘evergreen’, it’s more that they don’t always completely die down in the garden and commercial growers with heated greenhouses crop them in Winter.

There is a greater range available of hybrid types than I have reported today. To keep flowering through a very dry spell you might need to apply generous irrigation. Too much of an effort for me.

Propagation

Although the once flowering type 2 can be easily raised from self collected seed it is not worth the bother when they can be propagated so easily by division. I have never tried seed of the hybrid type but suspect that their variability might be a problem although you just might get a fine new variety.

Division is very successful provided you go very deep. Thrust your spade in a long way, more than a foot. Their tubers form a long way down. Most gardeners fail to do this and bring up a spadeful of chopped off stems which always die. Providing you bring up the intact tuber division it is difficult to fail.(even if you lose a few shoots). Even in Summer, but this would  be foolish unless you were moving.

Plants propagated in pots can be planted at any time of year as long as soil conditions are ok - not frozen, bone dry or flooded. Remember for summer planting you will need to water. 

For more tender varieties plant deeply and/or mulch very thickly.  The first two Winters are the hardest. By then strong very deep tubers will be  established  and be very well insulated.

What a difference a drought makes

This picture in May now seems a dream - now in September we have only once had proper rain

We have now suffered three months drought with barely an inch of rain. Its been very hot and even cloudy days have been windy. I write my posts well in advance. In this case long enough to eat my words!

It has become apparent in such extreme drought if they are not heavily watered the hybrid type are unable to support new growth of flowers. Watering established perennials goes against the grain for me but had Brenda not watered twice they would be in a very poor state now. Worse, the first strong flush of growth when it was still wet and windy were badly blown over!  Brenda is crowing. So much for my comment about not staking! It’s not quite been a disaster and they will be alright next year. Those Brenda heavily watered are now in late August making new flowers. Some I transplanted this Spring and perforce watered more frequently look really nice.

Link to Bunny Guiness article