HOW TO GROW...WITH ANNE SWITHINBANK
Fiery alstroemerias bring life to borders
IWONDER how many gardeners have been tempted by a beautiful Peruvian lily, planted it out and either watched their plant dwindle after successive winters, or die away altogether?
Treated well, alstroemerias can add spectacular colour to gardens from summer through to autumn, but they generally need a little more attention than average to make sure they take successfully.
Make the effort to nurse them past their first couple of winters and they’ll settle down to bloom year after year and spread into impressive colonies.
The secret of success is to understand the origins of these plants that are bred from species growing in grassland and mountain scree in South America. Enjoying a sunny, or at most lightly shaded, position in welldrained soil, after a couple of years the fleshy, rhizome-like tubers anchor themselves deeply in the ground enabling plants to withstand extremes of cold, wind and drought. Some of the showy hybrids are hardy to -12°C (10°F) but others are somewhat more tender and their ability to survive cold depends to a large extent on soil type. They will stand more chance of coming through winter in well-drained soils than heavy, wet clays.
To improve both extremes of soil, add lots of well-rotted garden compost or other soil conditioner and, if there is the least suspicion of poor drainage, plant into slightly mounded beds to raise roots above the general lie of the land. Some growers dig deep holes, line them with crocks and refill with some grit added for good measure.
Most important of all, especially in cold regions, is a deep mulch of chipped tree bark spread over the plants for winter. Let growth die back naturally first, cut down the old stems and then spread mulch 8in (20cm) deep over the top. By spring, weather and birds will have thinned it enough for new growth to push through, otherwise excess can be gathered up.