As we look back over events of last summer, such as the Jubilee and the Olympics, many summer bedding schemes in parks and gardens reflected the patriotic red, white and blue of the union flag.
The classic ingredients were red salvias, white alyssum and blue lobelias and if you’re aiming to do something similar this year, now is the time to be choosing varieties, ordering seeds and even, with lobelias, to prepare to sow seed. Lobelia erinus is a low growing, bushy or trailing perennial, native to southern Africa, usually grown as a half hardy annual. Different kinds have been selected and crossed with other species to produce the compact edging plants and cascading varieties familiar to gardeners today.
Lobelias are stalwarts in summer bedding schemes, containers and hanging baskets, and flower freely throughout the summer. The deep blue ‘Crystal Palace’ and ‘Mrs Clibran’ are tried and tested compact varieties, growing to about 4inches/10cm tall with a spread of around 6inches/15cm. ‘Cambridge Blue’ has a similar habit, but with light blue flowers. These make ideal edging plants. Trailing kinds, such as ‘Sapphire’, generally spread to around 12inches/30cm and look great in hanging baskets or tumbling down the sides of containers Trailing forms of Lobelia richardsonii are often sold as plants in 3inch/8cm pots in May. These have been very impressive with me in both sunny and cooler summers and even, along with dark leaved begonias, showed some degree of resistance to slugs, when neighbouring plants were being attacked during last summer’s downpours. They associate really well with just about everything, growing through other plants without over-powering them. Blue verbenas, orange petunias and pink ivy-leaved pelargoniums all make companions.
Lobelia seed is very fine and can be mixed with silver sand to help get an even distribution of seed over the surface of your compost. Sow the seeds on the surface and gently firm them with a tamper or the base of a pot. Don’t cover the seed with compost and don’t exclude light, as this helps germination. If you have a heated propagator and can maintain an even temperature of 65 degrees F (18 degrees C), germination will take around two to three weeks. When seedlings are large enough to handle, they can be transplanted.
Seedlings are too small to prick out individually and can be pricked out in groups of three. They will then need cooler, but warm conditions (around 50F/10C) and good light. As lobelia seed is so fine, it is sometimes available as coated seed, which can be directly sown into cells or pots, as can lobelia seedlings or plugs, which are also available at garden centres from February and can be directly planted into cells or pots. Grow seedlings on under glass in the usual way, hardening them off by gradually exposing them to cooler outdoor conditions in May and plant them out towards the end of May.
when the danger of frosts is past.
Once planted out in a reasonably sunny spot on moisture-retentive, but free-draining soil and kept watered for the first few weeks until they have established if the weather is dry, all they need then is sunshine. Given the right conditions, they will flower from June to September and into October until the first sharp frosts bring the season to a close.
We gardeners need to be optimists. Let’s hope this summer’s weather is a little sunnier and drier than last year’s.
Jobs for the month
Order vegetable, flower seeds.
If you have a heated propagator, sow seed of pelargoniums.
Sow a mangetout variety of pea indoors to produce pea shoots. Harvest when the shoots are about 6inches/15cm tall.
Prepare new planting plots by digging and adding manure, leaf mould or home-made compost.
January and February are usually the coldest months . Check that any bubble pack, hessian sacking or straw placed around plants and pots to protect them from the cold is still in place.