In your ornamental garden in June

General tasks

• For large potted plants that don't get repotted every year, a good general organic feed will really help.  Top dress with home made compost (worm compost is excellent) or use a liquid feed such as the Plant Food Concentrate  from The Organic Gardening Catalogue
• Keep pots and baskets well watered. As plants are growing vigorously and the June sun can be very strong, watering twice a day could be necessary in some cases.

• New plants should be watered in well at planting time, and during dry spells. When you plant, create a shallow dip around the plant base to hold water, and give a good soaking every couple of days, not a cupful twice a day. The aim is to encourage roots to extend deep down into the soil, seeking out moisture. Little and often watering methods encourage roots to develop close to the soil surface where they are more likely to dry out.

• Mulch around plants in beds and borders (and in large containers), to retain moisture. A thick layer of leafmould is the best mulch, but grass clippings or composted wood chippings are good alternatives. A layer of newspaper, covered over with grass mowings will help to suppress weeds and retain valuable moisture during long hot spells.
  

  See our factsheet on Mulches, weed prevention and control
  (Online access to factsheets requires members' password. Find out about becoming a Garden Organic member here.)
• Give your box and yew hedges and topiary an annual clip/trim. This is the very best time of year to do this. Give them a nice feed after clipping to help them recover.

Greenhouse

Greenhouse art

Members Jill and Neale Daniel share their way of combining horticulture and art!
‘I thought I would share an idea we have had to reduce the amount of greenhouse shade after you get past the hottest days of summer. It brings a smile to everyone who sees it.

We have a hot greenhouse for tomatoes and a warm greenhouse for other plants, so my wife Jill came up with the idea of altering the shading, painting the flowers on the right and wiping them off on the left.’

• Greenhouses and conservatories should be well ventilated, and shaded. If you're going away for even a couple of days, get someone to open doors and windows to prevent plants 'cooking'.

• For the more adventurous, palms, bananas, gingers and yams will start to throw out new leaves with abandon. Many palms do not enjoy full sun and if you can find a spot for them that offers a little shade in the afternoon they will be much happier.

• Houseplants such as ferns, Dieffenbachia ( Leopard Lily), Monstera ( Swiss Cheese plant), ivy, Marantha (Prayer plant), and Begonias, will suffer in strong sunlight on south-facing windowsills. Most of these plants originate from moist, semi-tropical conditions and prefer dappled sunlight. Move them to an east-facing spot where they will get early sun, but not bake in the afternoon, or simply move them outdoors to a sheltered, shady spot

• On the other hand, succulents such as cactus, yucca, agave and similar plants will thrive in the scorching afternoon glare.
  
• The temperatures should be high enough to use all types of biological controls in your glasshouse. Use the predatory mite Phytoselius for red spider mite, the tiny wasp, Aphidius for Aphids, the predatory mite Hypoaspis for control of sciarid fly, the parasitic wasp Encarsia for white fly and Cryptolaemus beetles for mealybugs. All require 18-20°C for a couple of hours a day, so make sure you can achieve these temperatures before you buy.

  Biological controls are available from the Organic Gardening Catalogue. Garden Organic members have online access to our factsheet:

  • Red spider Mite
  • Sciarid fly
  • Aphids

  Access to these factsheets requires members' password. Find out more about Garden Organic membership.

Lawn care

• Lawns don't need watering. The grass may not look at its best in a drought, but it is a great survivor and will come back again when it rains. Unless you have newly laid turf to water in, leave the lawn to look after itself.
• Don't mow the grass too short. Cutting height should be about 2.5cm for the summer.

• If you are thinking of buying a new mower, consider a 'mulching' or 'recycling' mower. These machines chop up the mowings very finely, then spread them evenly over the lawn. No more clumps of mowings walked into the house, and much time saved not having to empty the grass box.
• Lawns are very good for lying on and sun-bathing, on nice summer days. Be sure to use a sun block!

Pond management

• Ponds are an excellent resource for teaching children about ecology. Sit quietly by your pond for an hour and see how many creatures are living in the pond and see how many creatures visit the pond for a drink or to hunt.
• Try growing watercress in your pond, it is a British native and prefers slow moving water but will also perform well in a pond. It will crop throughout the summer months and will survive mild winters. Watercress seed can be purchased from The Organic Gardening Catalogue.
• There are many other edible aquatics that you can grow in your pond.
  Garden Organic members can see our factsheet on Edible aquatic plants.
  
  Access to these factsheets requires members' password. Find out more about Garden Organic membership.

What to plant in June

June is still a good time to plant grasses. Grasses only grow new roots in late spring and early summer, so now is the last chance to pick some and get them planted. There are many grasses to choose from, from small tufty clumps to tall wavy, elegant grasses.You can find grasses that are suitable for full shade or full sun and anywhere in between.

Hakonechloa macra 'Aureola'

Milium effusum 'Aureum'

Deschampsia flexuosa 'Tatra Gold'

Miscanthus sinensis

• For the shade try Hakonechloa macra 'Aureola' also Milium effusum 'Aureum', found by E.A. Bowles at Birmingham Botanic Gardens. This is a beautiful delicate golden grass worth a place in any garden.

• Deschampsia flexuosa 'Tatra Gold' is a small lime green, clump forming grass ideal for dry shade.

• Grasses for sunny spots are easy to find, if you have the room try a large Miscanthus, these are generally tall upright grasses with feathery flowers. Try Miscanthus sinesis or if you like your grasses tall and tropical looking try Miscanthus x giganteus.

Plants for free

• This is a good month to take cuttings from some plants, and you can save seed from others. Early flowering plants, such as Aquilegia and Hellebores , will be setting seed from now on. If you collect the seeds of Hellebores before they form a hard seed coat you can save yourself a lot of time and waiting. The seeds look black and shiny and are still a little bit soft and wet. Sow these seeds immediately and they will germinate in a few days instead of having to wait till the following spring.

  Take cuttings from hardy Fuchsias and Penstemons, particularly if you have bought a beautiful specimen at one of the many shows now taking place round the country. All these plant are very easy to propagate from cuttings. Simply cut below a node( leaf joint), strip off all the lower leaves except the top tip, put in a 5 to 7cm pot with cutting compost, place in a shady spot and finally pot up 4-6 weeks later.

  For detailed information on taking cuttings, consult a good gardening book.

Geranium sanguineum var. striatum


Geranium pratense 'Splish Splash'


Geranium renardii


Geranium himalayense


Geranium phaeum

Easy Perennials

This section gives you our suggestions of perennial plants that look good, are easy to grow and fairly free of pest and disease, making them a good bet for an organic garden. All plants marked with a * indicates an Award of Garden Merit (AGM) from the RHS.

Some favourites that are looking good this month are hardy geraniums.

Most hardy Geraniums are completely free of pests and disease and are very easy to grow. They come in a wide range of colours and habits that are also very good for attracting beneficial insects to the garden. Some of the native species and cultivars are particularly suited to our needs.

• Geranium sanguineum, from the limestone pavements in Yorkshire, is low and wide spreading with bright pink flowers and G. sanguineum var. striatum is a beautiful pale pink with deep rose veins. Both are good in full sun and flower from June onwards all through the summer.
• Another good native is Geranium pratense, which is a robust and vigorous plant with deeply cut leaves and dense heads of violet-blue flowers, good for part or full shade. There are 2 good varieties well worth acquiring - G. pratense "Mrs Kendall Clark" has blue-grey flowers with rose stripes and G. pratense "Striatum" ("Splish Splash") has blue and white mottled flowers. The pratenses can be cut to the ground after flowering and will re-grow a tidy clump of fresh leaves and may give a second flush of flowers.
• Geranium renardii has a very different leaf from other geraniums, which is soft, fleshy leaf and more rounded than deeply cut. It will grow in the shade or the sun, has a very pale pink almost white flower and a neat tidy habit, ideal for the front of the border. A close relative of Geranium renardii is the lovely, delicate Geranium 'Philippe Vapelle' it again has the soft fleshy leaf of G. renardii but with a five separate purple petals.
• Another ideal Geranium that is suitable for sun and shade is Geranium himalayense, which is from the Himalayas and is tough as old boots. It forms neat tidy clumps and spreads laterally by the roots, making it ideal for under-planting shrubs and for the front of the border.
• One of the very best Geraniums for using in deep shade is Geranium phaeum. This is a beautiful, delicate Geranium with small dark maroon flowers with slightly reflexed petals and deeply cut leaves. This is a very useful Geranium as it will grow in almost any location from deep shade to full sun. Look out for two other varieties of G. phaeum. G. phaeum var phaeum is a very dark variety with an almost black flower, it enjoys sun, shade or both and is very easy to grow and find at the garden centre. G. phaeum var lividum is similar in habit but has a beautiful lilac flower with small purple flecks on the petals. All three G. phaeum are lovely plants and worth finding for any garden.

Pest watch


Ladybird larvae
eat aphids

This is a busy month for pests, but fortunately the beneficials, such as hoverfly larvae, ladybirds and many others, should also be present in large numbers to deal with them.

• Check for sawfly attack on Solomon's Seal. Remove and destroy larvae on sight to break the cycle.

• Horse chestnut scale will often be found on ornamental Acers this month. Rub the colonies off with your fingers (wear gloves if you're squeamish), and check for the next couple of weeks that none have survived.

• Scale on bay trees growing outside can be a real nuisance, especially if the tree is large. Honeydew dropped by the scale insects causes sooty mould to develop on the leaves. It's hard to get rid of the pest, so just try to keep the leaves clean with strong jets of water.

  Check our Q&As for more details about scale and sawfly control
  
  See our factsheet on scale insects
  (Online access to factsheets requires members' password. Find out about becoming a Garden Organic member here.)

Disease watch


Rose blackspot

June is the month when many fungal leaf diseases start to appear. Powdery mildew, rusts and blackspot are common examples. The temperature/moisture combination is just right for their spores to germinate. Alarmingly, leaf blotches appear overnight on previously perfect plants.

Don't panic. These are rarely killer diseases - they just disfigure. Some years are worse than others. Good horticulture is the key to control and management.

• Remove and dispose of affected leaves, flowers and berries. Blackspot infected leaves on roses should be nipped off on sight.
• Don't over-feed plants. Lush growth is always more susceptible to disease attack.
• Mulch around the plant with a soil conditioner - leafmould is the favourite. It is low in nutrient, and high in micro-organisms.
• Keep plants watered in dry spells, but water at the base - avoid wetting leaves.

Powdery mildew is often a problem when plants are under stress, due to poor growth conditions. Plants growing by fences and walls invariably suffer dryness at the roots. Keep all wall/fence trained plants well watered - and mulch to retain moisture.

See our factsheets on Rose blackspot and Powdery mildew
(Online access to factsheets requires members' password. Find out about becoming a Garden Organic member here.)

See also our technical notes on organic rose growing (PDF 575Kb)

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