Gardening: Foam flower - a delightful flower in the summer garden

Foam flower is one of those little gems that are routinely passed over in the rush to admire bigger, more colourful flowers. And a gem it is. In fact, its botanical name tiarella means a small tiara or crown.

The flowers are produced on tall, slender stems that look so flimsy that you’d think they wouldn’t support much. But they are actually quite wiry and the weight of the small foamy flowers is not enough to give them a great test of strength. However, they are nicely carried over the foliage and they positively sparkle in the sunshine, each little flower a miniature explosion of light.

The flowers first appear in May and there is no better combination than deciduous azaleas over a carpet of foam flowers. Nothing looks so fresh – the large vividly coloured orange, red or yellow trumpet flowers of the azalea set off to perfection by the foaming masses of softly gentle flowers of the tiarella.

Flowering goes on for several weeks as new flower spikes replace the ones that go over, and this lasts well into late June. The timing of flowering starting and finishing varies with the season and also according to the coolness of the position of the garden and the place the plant is growing.

This flower is a native of North American woodlands and clearings and it is a very good ground cover – some might even say it is too good in that it can decide to take over when the conditions really suit it. But it is perfect for a garden where established shrubs or trees make it difficult to grow plants underneath. It spreads by creeping stolons and creeps out over the soil surface.

The foliage is evergreen, handsome in its own right, with pointed lobes, the leaves quite broad. It forms a dense mat of foliage to keep the weeds at bay, but does not grow tall itself, usually seen at 15cm to 30cm with the flowers over that. If there is a concern about this plant spreading too much, plant it where there is space to roam and it is not likely to be a problem. It is very natural in appearance and looks very well in a country garden.

While tiarella is bone-hardy, capable of withstanding the hardest frost due to its dry leaves and wiry stems, it can be affected by constant rain. For this reason, it needs to be grown in soil that is free-draining and leafy, as it is a woodland floor plant, it can cope with the relatively dry conditions under trees. It needs reasonably good light, so a touch of sunshine for part of the day would be perfect.

It is a member of the saxifrage family, its frothy head of small flowers being typical of the genus. There are several other family members grown as garden flowers. Heuchera has become very popular with remarkable coloured leaves. Tellima is a tall plant with nodding green flowers. It sets seeds in some gardens and can become a problem weed. The piggyback plant or tolmeia is better behaved and makes a good evergreen ground cover.

London pride is related too, with masses of foaming pink/white flowers on wiry stems. Bergenia is also part of the family, though bigger in all its parts. Vine weevil can affect these plants if peat is used at planting.

Lupin aphids

It is the time of year when reports abound of lupins collapsing in full flower, the flower spikes a solid mass of grey-green aphids or greenfly. This kind of greenfly is particularly large, with individual insects up to pea-sized and they can be present in sufficient numbers to encrust the stems. With many sucking mouthparts latched on to the succulent stems of lupin and drawing off sap, it is little surprise that the stem collapses, the flower falling over.

The natural predators, such as ladybirds and hoverflies, do not seem to halt this pest. Perhaps they are outnumbered, or perhaps the aphids are large enough to be able to fight off the predators. It may be necessary to spray the lupin plants with a garden insecticide to knock back this pest. Even with a complete clearance of the pest, there is a fair chance they will appear again, so watch out for them next year in the two weeks before the flowers colour.

Fruit & veg

It is a slow year in the vegetable garden, with stop-start growth. Slugs and snails have been a problem too and again it is essential to keep them in check as snails can do a lot of damage to small vegetable plants. Make any repeat sowings that are necessary. Spray against apple scab disease if the weather has long wet spells.

Flowers

Control weeds in flower beds and make sure that all containers are watered and given liquid fertiliser every two or three weeks, unless slow-release fertiliser was incorporated when potting. When the weather is damp, most people assume that pot plants’ needs for moisture have been met, but often that is not the case.

Lawns

Grass growth has been up and down with the temperature levels changing every few days. Lawns that were left too long for mowing have been skinned badly and this takes a while to grow out. It can be helped with an application of high-nitrogen fertiliser, but be careful not to overdo it or mowing can become heavy.

Trees & shrubs

Check all young trees, shrubs and roses for signs of drought. Despite the wet weather, any plant put in during the past year can struggle for moisture if they have not yet rooted out into the soil properly. Shrubs finished flowering should be pruned now if this is necessary. If there is room for them to grow, they should be left.

Greenhouse

Continue watering and feeding regularly to keep plants growing well. Damp down the floor of the greenhouse or polythene tunnel and give plenty of ventilation on sunny days, a little less on dull days to keep the temperature up. Watch for greenflies and red spider mites which tend to build up during this period.