If you're having trouble reading this from your email, click here to access it through your internet browser.

Oak Leaf Gardening Monthly Cuttings

Newsletter 56 - January 2016

What to do now

Ornamental plants

  • Order summer flowering bulbs, eg dahlias, cannas, ginger lilies, eucomis, gladioli, begonias and gloriosa.
  • Check on stored bulbs/tubers for signs of rot.
  • Plant or move shrubs, hedging, trees and roses.
  • Continue to take hardwood cuttings.
  • Knock deep snow off hedges and shrubs so the weight doesn’t splay or break branches.
  • Prune ivies, climbing hydrangeas and Virginia creepers.
  • Cut back the old growth on grasses (eg miscanthus and pampas grass).
  • Remove dead flowers and leaves from winter/spring bedding to keep it fresh.
  • Sow annuals such as calendula and sweet peas.
  • Start to sow tender perennials if you have a heated greenhouse/propagator.
Fruit and veg
  • Plant new fruit trees and bushes.
  • Prune congested apples and pears if you didn’t do them last month.
  • Prune back blackcurrants, white currants, redcurrants, gooseberries and autumn fruiting raspberries if you haven’t already done so.
  • Check that stored fruit and veg aren’t rotting.
  • Cover beds with black polythene or horticultural fleece where you want to plant early in the spring.
  • Sow early crops of salads, tomatoes, cabbage, cauliflowers, peas, broad beans and maincrop onions in a heated propagator.
  • Order seed potatoes, onion sets, asparagus crowns and artichokes.
General tasks
  • Once the 12th night has passed, start the new year being green by recycling your Christmas tree.
  • Clean out nesting boxes while they’re vacant.
  • Keep bird feeders topped up and use a kettle of boiling water to defrost bird baths.
  • Have a good sort through your shed and gardening equipment to ensure everything’s tidy and in good working order ready for spring.
  • Wash used pots and trays so they’re ready for spring sowings.
  • While plants have died back, take the opportunity to repair and treat timber structures in the garden.
  • Brush snow off your greenhouse roof.
  • Make sure your greenhouse heater continues to work effectively.
  • Ventilate greenhouses on warmer days to keep the air circulating and reduce humidity.
Plant of the monthHelleborus foetidus

Helleborus foetidus is an evergreen, herbaceous perennial which flowers from later winter through to spring with pale green, downward facing flowers. It's perfect for woodland borders or in dappled shade (for example underplanting roses). It requires little maintenance, except for the removal of older, tattered leaves. Find out more...

Problem of the month

Stem eelworms move through the soil and burrow into plants, eating them from the inside out. The damage can be minor but in many cases it will be more serious and can kill the plant. The eelworms are only 1 to 2mm in size and the symptoms are often confused with other problems. Fruit (especially strawberries), vegetables and ornamental plants can all be attacked by this pest. They can remain dormant in the soil for several years, so once you've had an infestation it's best to remove all susceptible plants within 1 metre of the source and re-plant with less vulnerable plants for the next 2 to 3 years. Find out more...

In the news

Daffodils out in Lincolnshire fields

Pack of Narcissus 'Spring Dawn'As daffodils make an early appearance around the south of the country, Taylors Bulbs are seeing early growth in their daffodil fields in South Lincolnshire. While they expect to see December flowering about one in every three years, this year's mild weather has lead to accelerated growth as well as untimely blooms from their early variety Narcissus 'Spring Dawn'.

Restoration of Highland woodlands

Following a 11,000 hectare survey of ancient woodland sites, the Woodland Trust Scotland have started the restoration of 1,000 hectares of woods. Project manager Peter Lowe explained that the restoration is particularly important now because so many plantations are coming to maturity and their future management needs to be agreed.


Planting trees

Cedrus libaniWinter is an ideal time to plant trees. Water is freely available to them and this dormant period (for many trees) gives new additions a chance to establish before active growth starts again. Just make sure that the soil isn't waterlogged or frozen before you plant.

While preparing your planting hole keep the plant's roots covered and in the shade to ensure that they don't dry out. If the tree is in a pot then water it well but don't take it out until the last minute. If you have a rootballed or bare-rooted tree then give the roots a good soak in water for 30 minutes before planting.

If you have bought a bare-rooted or rootballed tree but aren't able to plant it immediately you can 'heel it in' for a few weeks before planting it. This entails digging a shallow trench and laying the tree in it at an angle so its roots are covered and don't dry out. Potted trees can stay in their pots while you're waiting to plant them, but pay close attention to watering them as the roots will dry out quickly.

Dig a hole which is 2 to 3 times as wide as the rootball and 1.5 times the depth. There's debate as to whether a round or square hole is best for encouraging root growth, so you can choose whichever shape you like! If you're planting the tree in a lawn, remove a circle of turf at least 1m in diameter.

Add some organic matter (eg well rotted manure or garden compost) to the bottom of the hole and to the soil you removed. Use a spade to break up the soil at the bottom of the hole so the organic matter is dug in a little. Then gently firm the base of the hole with your foot to ensure that there aren't air holes which will cause the tree to sink after it's planted. Break up the removed soil so it will fill back in well without leaving gaps.

Check the depth of your hole by putting the tree into it briefly and laying a cane across the hole against the stem so you can see where the soil will come up to. The tree should be planted to the same depth as it was at the nursery you bought it from (in the case of bare-rooted plants you should be able to see the soil line on the stem). If you can't tell where it was planted to, the best solution is to plant it so that the very first signs of roots on the stem are level with the soil surface.

If you have a bare-rooted tree, create a little dome with soil at the bottom of your planting hole. You'll spread the tree's roots out before you plant it, so you can then sit the nub of the roots on the dome and spread them downwards around it.

If you are using mycorrhizal fungi (eg Rootgrow) to help the tree establish, now's the time to sprinkle it at the bottom of the hole. Don't dig it in as the fungi need to be in direct contact with the roots.

Drive a stake into the soil on what will be the windward side of the plant. This can either be driven in straight so it's in line with the trunk, or at a 45° angle so the top is pointing towards the prevailing wind. It's very important to put the stake in before the plant to avoid damaging the roots.

At this point you can also put a plastic tube into the soil (such as a plastic drainpipe) near where the roots will be, so that its top is sticking up above soil level. This will help you to water the plant as it establishes, as you can pour water down the pipe to get it straight to the roots. Biodegradable tubing is also available, which will rot safely away after a couple of years.

Remove the tree from its pot or fabric wrapping (unless it comes with instructions to plant it in the wrapping). If it's bare-rooted, spread the roots out. Place the tree in your planting hole, checking again that the depth is correct. Push some of the removed soil back into the hole then very gently shake the tree up and down so that the soil settles around the roots. Gently firm the soil down with your foot. Repeat this process until the hole is filled.

Use a tie to secure the tree to the stake, with a spacer to ensure that the tree isn't rubbing against the stake. Nail the tie to the stake (not to the tree!) to keep it in place. Put protection around the stem if deer or rabbits are a problem.

Water the tree well at its base then add a layer of organic matter as a mulch, ensuring that the mulch doesn't touch the stem of the tree as this can cause rotting. You can also top dress with fertiliser if you wish.

Ensure that the tree is kept well watered for the first couple of years as it establishes, particularly over the summer months. Refresh the mulch annually and top dress with a general purpose fertiliser if the soil is poor. Make sure that an area of at least 1m diameter around the tree is kept free of weeds and other plants while the tree gets established. Check the stake tie a couple of times a year and loosen it as the stem thickens. The stake can be removed after 3 years.


What's on this month

Get out and about in the new year with these garden events:

  • 10th January - Bristol Potato Day And Seed Fair, Southville Centre, Southville, Bristol.
  • 13th January - Practical Pruning Course, Ryton Organic Gardens, Nr Coventry.
  • 14th January - 'Connecting People With Plants For Three Centuries' Talk, Devon Gardens Trust, Rowe Hall, Exeter, Devon.
  • 16th & 17th January - Pruning Old Fruit Trees Course, Brighton Permaculture Trust, Sussex.
  • 20th January - The Gravel Garden In Winter, The Beth Chatto Gardens, Colchester, Essex.
  • 20th January - New Year Ideas Talk, Gordale Garden And Home Centre, South Wirral, Cheshire.
  • 23rd January - Weekend Shrub Pruning Course, Waterperry Gardens, Nr Wheatley, Oxfordshire.
  • 30th & 31st January - Snowdrop Weekend, National Botanic Garden of Wales, Llanarthne, Carmarthenshire.