Summer Newsletter 2017

We’ve all enjoyed the wonderfully warm and sunny spring and early summer months, with seemingly endless long hot days, blue skies and sunshine, but now, here I am, at the end of July, sitting in the office with a fleece on listening to the rain! What on earth is going on? Mind you, we certainly needed a bit of rain to give our gardens and open spaces a boost, so as long as the temperatures rise again, and the rain clouds disappear, we should be grateful for that. Somehow, watering with a hose or irrigation system just isn’t a patch on what a really good downpour of rain does for our gardens. Don’t forget that most things could also really use a nutritional boost, so if you’re not already feeding your beds, borders and lawns, start doing so now.

The early heat and sun we enjoyed means that many gardens are well ahead of where they’d normally be at this time, and in need of an injection of colour. Luckily, we continue to bring in some glorious plants to do just that for you.

The front tables are an inspiration at the moment – they have been put together to emulate ‘prairie’ planting … a mixture of grasses alongside tall willowy plants, such as Verbena bonariensis and Coreopsis, injected with vibrant splashes of hot colour from Salvia, Echinacea and Rudbeckia. Just glorious.

The Hydrangeas are the superstars at this time of year, whether you like to keep it simple and elegant with white or cream flowers, or blousy and boisterous with red, pink and blue. If your hydrangeas, or anything else for that matter, need some support as their huge blooms start to weigh them down, don’t forget we have both the rusty iron plant supports and the simpler metal ones with a plastic coating. You’ll find them on the upper site. Oh, and please check out the amazing tree ferns while you’re up there! They are spectacular. (I finally treated myself to one earlier this year, which is positioned in my gloomy side return, where I can see it from both the kitchen and study windows, and it has absolutely transformed the space.)

Of course, the range of edibles available is diminishing rapidly at this time of year, but we still have plenty of the basic herbs - including rosemary, thyme, sage, parsley and coriander – and some tomato, chilli and pepper plants too.

If you’re itching to plant something now from seed, it’s not too late to start growing simple cut-and-come-again leaves or leafy herbs, such as rocket. In a month or so you could start your sweet peas off for next year (they’re always best sown in the autumn and put in a cold frame over winter). And of course at the end of August we’ll get our spring bulb collection in …. the year goes by quickly, doesn’t it??

However, for many of us, this period of the gardening year is all about spending less time doing and more time enjoying. After all, we all know how much there will be to do in the autumn months, so kick back and relax a bit while you can. Warm long evenings with friends and family spent outside, enjoying the fragrance surrounding you, perhaps with a barbeque on the go, are a joy. We still have plenty of charcoal and wood, by the way, so stock up if you plan on hosting a few over the next few weeks.

One of the things I love about the summer months is being able to keep the doors and windows wide open, bringing the sounds and smells of the outside in. When the weather doesn’t allow that, I try to have at least one bunch of flowers in the house, but an alternative quick cheat, to get the scent of the outdoors inside, is to grab something from the range of nature inspired candles and diffusers we have in stock. You can subtly fragrance your home this way, and I’m delighted to tell you that we now have a selection of True Grace ‘Walled Garden’, which are more competitively priced than the glass votives, as they are in tins. Delectable scents include Cucumber, Sage, Lemon Tree, Chamomile, Garden Rose and Rhubarb.

I’ll sign off and pass over to Sally, with her ‘Garden Tasks’, but very much hope to see you at the centre soon.

Karen

Garden jobs

The British summer is notoriously unpredictable for the garden, with hot temperatures interrupted by heavy rain. Hopefully we will have some fine days when you will be outside with time to spare.

My top two jobs for summer...

1.Enjoy time in the garden: potter about, deadheading, weeding and keeping an eye out for problems but also spotting a new plant combination from a different angle, or admiring a particularly lovely plant, just doing its thing.

2. Plant supports - if heavy rain or winds are forecast, check plant ties and plant supports to protect blooms from damage.

General maintenance

• Weeding: keep weeds down by hoeing the borders. Weeds compete with plants for water and nutrients, so it’s worth keeping on top of them.
• Watering: keep everything watered, especially pots and containers, recently planted trees, shrubs and borders. Water in the early morning or evening, when there will be less evaporation. Water the compost, not the leaves.
• Feeding: plants need nutrients. New compost contains nutrients to support plants for 5-6 weeks, thereafter you need to use suitable fertilisers. Established perennials and shrubs which are not performing well, containers of summer bedding, and house plants will all benefit from regular feeding with the right fertiliser. Know whether your plant is acid loving, such as Azalea, Rhododendron, Pieris or Camellia, therefore requiring an ericaceous fertiliser.
• Deadheading: most plants will flower for longer if faded flowers are removed. Deadhead roses by cutting back to a bud in a leaf axil lower down the stem thus encouraging strong new shoots which will produce more flowers, often well into the autumn. With bedding plants, deadheading stops the plants setting seed, forcing them to produce more flowers. Some plants, such as petunias, may get straggly and can be cut back hard with secateurs and fed with a high potash fertiliser to encourage new growth.
• Camellia and other early spring flowering shrubs set their flowers through the summer. Make sure you water and feed them regularly, especially container grown specimens, for a good show next spring.
• Remove spent flower spikes on lavender, ahead of cutting the whole plant back when it has finished flowering in the autumn.
• Cut back straggly and faded perennials to keep borders tidy and then give them a feed. Tall plants such as Achilleas can flop and smother smaller plants. Trim them back and they may flower again later. If you haven't already cut back hardy geraniums, do it now to tidy them up and they will produce new growth and may flower again. Feed and water to encourage new growth.
• Ponds: water evaporates very quickly in hot weather, so check ponds regularly and top up water levels if necessary, but only with rainwater. It is harmful for wildlife in the pond if you use tap water. Remove yellowing leaves and fading flowers from plants around the pond and remove them: plant debris in the water can raise nutrient levels which in turn encourages algae.

Container gardening

• You will get to know how often to water large container grown plants, but smaller containers and baskets need watering every day, or, if temperatures are high, twice a day.
• Feed hanging baskets and window boxes with a high potassium feed to encourage continued flowering of your summer displays.
• There are lots of permanent planting options for containers too: for shade, try evergreen Heuchera, ferns and Liriope; for a sunny spot, how about Echinacea, Crocosmia, or perhaps an ornamental grass. Enjoy plants in a container this year, and plant them out into the garden next spring. It’s not too late to plant a container or two of herbs to enjoy in the kitchen, or in your cocktails.

Pruning

• Summer prune Wisteria by cutting the long wispy shoots back to 5 buds. For guidance on this, look at our Pruning Wisteria notes on our website.
• Remove unwanted growth from trees. Many trees and shrubs produce a mass of shoots at the base, which need to be removed because they sap energy and strength from the plant.
• Prune any remaining early summer flowering shrubs such as Philadelphus. Flowered growth should be cut to a strong lower shoot.
• Remove any shoots with plain leaves on variegated plants such as Euonymus.
• Trim conifer hedges such as Leylandii to keep under control. Yew hedges and topiary can be cut in August.

Planting

• If a gap appears in the border, or you find a pot which needs filling, there are plenty of options. Introduce some late summer perennials which will flower into the autumn - Japanese anemones, Crocosmia, Penstemon, Sedums short and tall - there are lots of plants which will flower until the first frosts, and may provide attractive seed heads through the winter.
• Did you forget some of your plants before they appeared earlier this year? Take some pictures to remind you what the border looks like in summer so that when you’re looking for a space to pop a new favourite next spring, you don’t plant on top of a dormant late summer perennial.
• Do you have room for a splash of autumn colour? Every garden should have a tree or shrub to provide glorious reds and oranges in the fall.
• Make sure you plant well with a big hole, good compost, Rootgrow and fertiliser, soak the plants beforehand and then water in well.

Fruit, vegetables and herbs

• Everything in the vegetable garden or allotment will need attention at some stage, whether supporting tall crops, protecting from slug damage, or harvesting.
• Continue harvesting summer fruiting raspberries and when finished, cut out fruited canes to ground level and tie in new healthy canes.
• Keep birds and squirrels off berries with netting.
• Harvest your fruit trees - cherries, plums, peaches, nectarines and apricots should be ready. Early varieties of apple trees will be ready towards the end of the month
• Blueberries in containers must be kept watered, ideally with rain water or soft water.
• Remember to feed lemons and other citrus fruit trees throughout summer with a special citrus fertilizer.
• Apply a high-potash fertiliser such as tomato food once fruits start to form on tomatoes, peppers, cucumber and aubergines.
• Water runner beans and tomatoes (and many other crops) regularly. Tomatoes should be kept evenly moist: irregular watering can cause fruit to split.
• Pick out the side shoots of tomatoes so that you maintain one main stem. Remove leaves lower down on the plant to help with air circulation and prevent disease.
• Check tomatoes for signs of fruit splitting and blossom end rot. Remove damaged fruit and ensure consistent watering to limit further damage.
• When beans reach the top of their supports, pinch out the leading shoot, to encourage more side shoots and beans lower down.
• Pick herbs regularly to encourage fresh shoots. Most herbs will benefit from being trimmed occasionally with garden shears to encourage a flush of new growth.
• Sow autumn and winter salads. Lambs lettuce, rocket and many mixed leaf seeds can be sown for extended harvesting. There are many cut and come again varieties.

Lawns

• Continue mowing and adjust the height of the blades when necessary. The general consensus is to raise the blades if the weather is hot, removing less grass.
• Recently sown or turfed lawns need a good soaking every few days, so that the water gets down to the roots.

Pests and diseases

• Fungal diseases such as Box Blight and rose black spot thrive in warm wet weather conditions. Take preventative action - healthier plants are more resistant - and apply appropriate treatments as soon as you see signs of disease.
• Warm weather can encourage pests. Greenfly and black fly can multiply really quickly and it can be difficult to keep on top of them. Think about building up diversity in the garden by planting a variety of plants, which will attract beneficial insects and other wildlife, improving the balance of pests and predators.
• Slug and snail populations continue to thrive. Choose your preferred method of control: wool pellets and Strulch create a barrier which slugs and snails are reluctant to cross; copper tape around pots delivers a sharp shock; anti-slug bait or pellets should be used thinly. A customer recently told us of his success in placing iceberg lettuce leaves around prized plants, which are eaten in preference to the plant - it might be worth a try!
• Watch out for powdery mildew, on roses and honeysuckle particularly. Remove affected plant debris, water and mulch, and if possible improve air circulation around the plant. If necessary, treat with an appropriate fungicide.

Wildlife

• Keep supplies of food and water going for the birds. If they are used to finding food in your garden, they will continue to visit. Birds are your ally when it comes to slugs and snails.

Holidays

Before you go away…

• Cut back bedding plants and give them a feed - hopefully they will be full of flower when you return.
• Group containers together in a shady spot if possible and ask a friend or neighbour to water them. Return the favour when they go away!
• If somebody is looking after your veg patch, invite them to enjoy tomatoes, beans and other fruit and vegetables, which will ensure that the supply continues when you return.

Plant Focus - Hydrangea

Hydrangea is a genus of 70 or more species of flowering shrubs, native mainly to southern and eastern Asia and the Americas. Most are shrubs which vary in height between 1 and 3 metres, although some, such as H. petiolaris are climbers which will scramble up walls or trees. The majority of Hydrangea are deciduous but there is an evergreen climbing Hydrangea seemanii.

Flower shapes: the majority of the coloured Hydrangea macrophylla are mophead, big round balls of flower, and some are lacecap, with flat flowerheads of small flowers surrounded by outer rings of larger flowers which have showy sepals or tepals. H. macrophylla have been bred to cover a wide range of flower colour from white through pinks, reds, blues, purples and greens. Hydrangea arborescens 'Annabelle' is a large white flowered shrub which provides interest for 6 months or more, with its winter seedheads. Hydrangea paniculata such as Limelight, Kyushu and others have cone shaped flowerheads which are predominantly white, some with hints of green or pink.

There are 2 Climbing hydrangeas: H. petiolaris and H. seemanii which have aerial roots, enabling them to cling onto whatever they are climbing up.

Planting: most Hydrangea thrive in sun or partial shade. They like a moist but well drained soil and are quite thirsty, so keep them well watered particularly when first planted. Hydrangeas give their best blue flowers on acidic soils with pH5.5: to keep the blue tone, the pH shouldn’t rise above 6.5. Incorporate some ericaceous compost when planting.

Pruning: Remove faded flowerheads in spring after the danger of frosts, cutting back the flowered stems to a strong pair of buds. Remove crossing and diseased shoots. Once established, remove a quarter to a third of the shoots to the base of the plant. Paniculatas flower on new wood so can be pruned by cutting down to about 18in in spring. Mulch young plants with a well-rotted manure or compost in spring.

Planting companions: underplanting with early spring bulbs such as dwarf narcissi, scilla, hyacinth and others will provide interest before the Hydrangea come into leaf and flower. Companion plants for winter interest might be late season grasses such as Miscanthus, Pennisetum or Molinia.

Finally

London parks are full of fabulous herbaceous borders and wildflower meadows, which are well worth visiting. Local gardens continue to open during the summer for charity, check the NGS yellow book and Dulwich guide - be inspired!

Happy gardening

Sally