Oak Leaf Gardening Monthly Cuttings
Newsletter 39 - August 2014
What to do now

Ornamental plants

  • Carry on deadheading, particularly repeat-flowering roses, and cut back flower spikes on perennials which have finished flowering.
  • Trim laurel, beech, hornbeam, leylandii, thuja, lavender, rosemary and santolina hedges.
  • Prune summer flowering shrubs such as lilacs and mock oranges as soon as they have finished flowering.
  • Get plants for free by taking cuttings from pinks, verbenas, penstemons and osteospermums.
  • At the end of the month take softwood cuttings from pelargoniums, fuchsias and other tender plants you want to keep over winter.
  • Rhizomatous woodland anemones can be divided late this month or early September (Japanese ones can also be divided but this may check their growth).
  • Clear older and rotting waterlily leaves from ponds and top up the water level if required.
  • Plant autumn flowering bulbs.
  • Start to force bulbs, such as hyacinths, for Christmas flowers.
Fruit and veg
  • Sow early carrots, peas, turnips, parsley, lettuce, baby spinach leaves, kohl rabi, winter spinach, coriander, spring cabbages, pak choi and Chinese cabbage.
  • Harvest blackberries, loganberries, peaches, nectarines, apricots, summer raspberries, early apples, French beans, runner beans, lettuce, beetroot, turnips, courgettes, onions, leeks, marrows, calabrese broccoli, summer squashes, sweetcorn, second early potatoes, tomatoes, globe artichokes and greenhouse grown tomatoes, peppers, aubergines, cucumbers and melons.
  • Pinch out outdoor tomatoes (nipping off the top of the plant). Keep on feeding indoor tomatoes, pinching out shoots and removing yellowing leaves.
  • Prune gooseberries, redcurrants, blackcurrants, summer fruiting raspberry canes, peaches, apples and fan-trained fruit trees.
  • Cut strawberry runners from the parent plants – layer them into pots first if you want more plants.
General tasks
  • Keep on weeding, watering and feeding, particularly newly planted specimens and container grown plants.
  • Ventilate your greenhouse well in hot weather, add extra shading if needed and damp it down regularly.
  • Keep an eye on sticky fly traps in greenhouses so you can monitor pest levels.
  • Raise your lawn mower's cutting height, or mow less frequently, in dry weather.
  • Start saving seeds from plants which have finished flowering.
Plant of the monthMonarda 'Violet Queen'

Monarda 'Violet Queen' is a perennial bergamot which flowers from June to September with a display of lavender-purple flowers and aromatic foliage. Deadhead regularly to keep it flowering throughout the summer and divide it every three years to maintain its vigour. Find out more...

Problem of the monthLesser Willow Sawfly

The lesser willow sawfly is most prevalent over the summer months and can affect any willow shrub or tree and some aspens. The larvae munch their way through leaves and a severe attack can defoliate an entire plant.

Remove and destroy affected parts to control an infestation. Find out more...

In the news

DEFRA urge public to protect bees

DEFRA, who will be publishing their national strategy for pollinators this autumn, is urging the public to take steps to help protect the bee population. They recommend five actions:

  1. Grow more nectar/pollen rich plants.
  2. Leave patches of land to grow wild.
  3. Cut grass less often.
  4. Avoid disturbing nesting or hibernating insects.
  5. Think carefully about whether to use pesticides.

US trees save 850 lives each year

A study by the US Forest Service has shown that trees in the USA save more than 850 lives and prevent 670,000 cases of acute respiratory symptoms each year through pollution reduction. The research indicates that the greatest benefits to human health come from trees in urban environments. They estimate the annual value of these health effects to be almost $7billion (£4billion).

Army help to save Birmingham island

60 reservists from the Field Squadron of Royal Monmouthshire Royal Engineers were among a team who have saved the 'hidden gem' island in the lake of Brookvale Park in Birmingham. The island had been eroding and the wildlife it sustained was at risk. The team re-built the island's shoreline with rock filled gabions, which should sustain it for at least another 50 years.


How to save seeds from your garden

Collecting seeds from your garden is a great way to get new plants for free, plus you can swap them with friends or at organised seed swaps.

When collecting seeds from hybrids you may find that the resulting plants are different (for example in flower colour or size) to the original or, in some cases, will not grow at all because the seeds are sterile. But sometimes the diversity can bring pleasing results and it can be fun to see what’s going to appear.

How to collect seeds

There are different methods to collect seeds, depending on the type of fruit. When the seeds are contained in pods (such as Nigella seedheads, shown below) you should remove the pod from the plant when it’s ripe, but before it opens. Keep it in a paper bag, or between sheets of newspaper, in a warm room and they should open and shed their seeds for you to gather up. The same method can be used for catkins or cones.

Nigella seedheads

Winged fruit (such as from acers) should be picked from the plant when they’re ripe. You can either leave the wings on or remove them to make it easier to handle the fruit.

Nuts can be removed from the plant when still green, or when ripe and ready to fall – the method will vary slightly from plant to plant. Remove the outer husks before sowing, but retain the shell of the nut.

Fleshy fruits (such as berries) should be collected just as they turn from green to their ripe colour. If the fruit is large (eg apples) you can cut it open and take the seeds out by hand. For smaller fruit (such as holly berries) place the fruits in a sieve and mash them up under running water. Put the resulting pulp in a container full of water, give it a shake and allow the contents to settle. Then gently pour the pulp and water out of the jar, which should leave the seeds at the bottom. Dry them on paper towels.

How to sow or save them

Always discard any seeds which appear to have imperfections or damage, and any which show signs of disease or pests. If you have used the jar method to separate fleshy fruit from its seeds, don’t use any seeds which floated as these will be dead.

If you want to plant the seeds yourself then you can do so straight away. Find out about sowing seeds. If you want to store them then most seeds are best kept in paper bags within an airtight container. Add desiccant to remove excess moisture (like those little silica gel sachets you often get in shop packaging) to prevent too much moisture accumulating. Some seeds, such as walnut and oak seeds, need to be kept moist, so store these in damp vermiculite or sand. If possible store the seeds in your fridge as this will help them keep for longer.

Find out more about collecting seeds...

What's on this month

Enjoy the sunshine while it lasts by visiting one of the many gardening events on this month:

  • 1st to 2nd August - Taunton Flower Show, Vivary Park and Wilton Lands, Taunton, Somerset.
  • 2nd to 3rd August - Pruning And Propagating Herbs, Woburn Abbey and Gardens, Woburn, Bedfordshire.
  • 6th, 9th, 10th, 20th & 31st August - Open Days For NGS, National Collection of Helenium and Centaurea, Yew Tree House, Hankelow, Cheshire.
  • 7th August - Plants For Free; Propagation Event, Logan Botanic Garden, Stranraer, Dumfries and Galloway.
  • 7th to 18th August - Surrey Sculpture Society Exhibition, Loseley Park, Guildford, Surrey.
  • 8th August - Gardener's Guided Walk, Hill Close Gardens, Warwick.
  • 8th to 9th August - Shrewsbury Flower Show, The Quarry Park, Shrewsbury, Shropshire.
  • 14th to 17th August - Southport Flower Show, Victoria Park, Southport, Merseyside.
  • 16th to 17th August - British Gladiolus And Gough Park Allotment Show, Capel Manor Gardens, Enfield, Middlesex.
  • 23rd to 25th August - Summer Craft And Garden Fair, Kingston Lacy Park, Wimborne Minster, Dorset.
  • 23rd to 25th August - Norfolk All About Gardening Show, Norfolk Showground, Norfolk.
  • 30th August - Kitchen Garden Open Day, Chiswick House Gardens, London.