Alstroemeria question

Jane McGary
Fri, 01 Jun 2012 10:09:39 PDT
Mary Sue forwarded this question to the website:
> >The alstroemeria is one of my favorite cut flowers and wish to grow
> >them in a new perennial bed. When is the best time to plant the
> >bulbs? Which varieties would be best for Southern Illinois growing

The alstros grown for cut flowers are hybrids that are selected for 
stiff stems and rather tubular flowers that can be packed closely for 
shipping. I think most if not all of these are too tender for outdoor 
cultivation in Illinois. They are generally grown in greenhouses.

Alstroemeria do not grow from bulbs. They have crowns with growing 
points and tuberous storage roots, rather like a Dahlia but not as 
compact. Some of them (e.g., A. ligtu) can produce new growth from 
detached storage roots, while others will produce growth only from a 
crown. They are pretty easy to grow from seed, flowering in the third 
or fourth year. The best time to plant them is in fall when the 
crowns are dormant.

Alstroemeria pulchella (syn. A. psittacina) is one of the hardier 
species and is also tolerant of summer water, but it is not as showy 
as the cutflower kinds. A. aurea is notably hardy and grows in the 
mid elevations of the southern Andes, but it can be quite invasive 
where suited, as can A. ligtu. It comes in orange and yellow. At my 
former garden where winter lows often reached the mid teens F, I grew 
the very showy F. ligtu subsp. incarnata and the scarlet F. ligtu 
subsp. simsii outdoors in a high berm of sand and gravel, not watered 
in summer (it does not rain here in summer). Another species that is 
succeeding outdoors in similar conditions is A. angustifolia, which 
is not so showy but suitable for cutting.

The alstros most likely to be found in garden centers are the 
Princess Strain, a series of low-growing hybrids. The different 
colors seem to vary in winter hardiness but I would not trust any of 
them below about 25 F. Their foliage and the markings on their 
flowers suggest that they are derived in part from the strictly 
coastal A. pelegrina, which is also short and compact rather than lax 
and trailing like most other western South American species. If 
purchased in flower, they should be grown on in their original pots 
until they start to wither, then allowed to go dry, and planted in 
fall while dormant. Even A. pelegrina, which grows within the ocean 
spray zone (if not indeed high-tide line) on rocky beaches, is 
dormant part of the year. I think another species used in these 
hybrids (especially the purple ones) is A. philippii. also coastal.

So the short answer to your question is that a "perennial bed" in 
southern Illinois is probably not the place for anything but A. aurea 
(sometimes sold under its former name A. aurantiaca) or maybe A. pulchella.

Jane McGary
Portland, Oregon, USA

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