Perennial plants: Lift, divide, repeat Now is the time to divide perennials, spring divide perennials
With many plants just revealing themselves after winter hibernation, it seems that last thing you’d want to do is dig them up. But for many, it will be doing them, and you , a favour. This is my ethos for perennial plants: lift, divide, repeat.
Some require this radical attention to maintain their vigour. Others to curb it. Or at least reduce the impact of it. That could be to stop a plant dominating an area, or to be able to use some of it to make a bigger display with more impact, or to split it and use the same plant to maintain the repetition.
Repeating the same plant in a border or adjacent borders helps to tie the scheme together. The same thing works with plants that are of similar colour and height. Using the same plants occasionally, or the same few plants in a repeating pattern adds cohesion. Otherwise there would a jumbled flow of individual plants, with nothing to bring it together.
Some plants either can be split, or need to be split, every 3-4 years. Some others can be done every two years, and sometimes more frequently than that. If the conditions are just perfect you can double the stock every year. This has happened in my garden with some crocosmias, and geraniums.
Self-seeding plant factory
In addition there are those that self-seed, providing a random imbalance of repeating that is entirely natural. These don’t actually need to be split, but it is inevitable that some will need to be moved. So, in effect, the same rules apply.
The small area of vacant soil at the front of borders is a favourite setting place for foxgloves, verbascums and verbenas. Sometimes they have found the perfect place to grow. But there is only so many 6ft high flowers you want at the front of the border.
Other great self-seeders include eryngium, various poppies, cornflowers, nasturtiums and marigolds.
Don’t be afraid to split your border plants now. They’ll forgive you. Remember, for perennial plants:lift, divide, repeat.
Using Dogwood for winter colour intense winter colour dogwood coloured stems
Many gardeners “in the know” will now have borders featuring the coloured stems of dogwood. These vary from deep purple to a whiter shade of pale, with reds, oranges, green and yellow. They know the secret of using dogwood for winter colour.
And in the summer these same plants offer strong growth with interesting foliage and flower.
Established Dogwood plants are available from garden centres in the spring, but at £12 – £20 each it will be expensive to create the sort of block colour impact that gets them noticed.
The best time to buy is early winter, when rooted stems can be bought for as little as £1 each. The more popular varieties, such as Midwinter Fire, will cost more. But the price of bare root canes reduces the more you buy.
I have used dogwoods for a few years now, both for the colour and for the winter framework. When they are cut back in the spring, the shorter framework provides support for emerging bulbs and perennials. So they earn their keep more than once.
Where to see dogwood for winter colour
A place that offers an idea of the sort of impact these plants provide is Dorney lake. I go there occasionally to drop my boy off to row or cycle, and always stop to look at the flowing banks of colour. It reminds of opening a large set of coloured pencils for the first time, seeing the colour themes grouped together, transforming from one shade to the next.
I also like the garden at RHS Wisley, where the dogwoods are planted closer to the water, with paths meandering through. From the opposite side of the pond you can see them reflected in the water, amplifying the intensity of the colour.
Both these places use other plants with similar properties to accentuate the effects. At Dorney a golden stemmed Willow provides intense yellow, while Wisley uses the ghostly Rubus brambles to provide a white foil.
Unless you have a significant garden that is likely to be where the large colour block concept ends. But you can use dogwood for winter colour in the smallest garden, using just a few plants. But in order to see the intensity of one colour there needs to be another present, rather like a straight man; Laurel and Hardy, Morecambe and Wise or Barker and Corbett.
Using just green or just red won’t do because you can’t see quite how green or red it really is. I use other dogwood colours, or other coloured stems, to provide the contrast, but anything that provides a backdrop will do.
How to get that intense stem colour dogwood for winter colour
The best colour shows on the newest stems. And that implies that you have to cut off the old ones – mostly – every year. Do it while the plant is dormant, normally by the end of February. But delaying pruning until later will maximise the colour show. In established plants, wait until the new leaves start to show, then either coppice to a low stump, or pollard for a mid-height effect.
The best time to prune for most of us is when you have time to do it. But to get the best result of strong coloured stems next winter, prune before leaf growth really gets going. Make your stem reduction before the plants energy moves to the leaves, or re-growth is impaired. That leaves a window from Late February to late March, depending on how warm it is.
Dogwood is a plant group that will enhance any garden, one I can’t contemplate being without.
Using dogwood for winter colour workshop
This spring I will show you how to prune your dogwood for winter colour, and what to do with the cut stems afterwards. I use them to create cuttings for more plants, or as cut stems in a tall vase for the hall way or lounge.
Pruning garden plants How to prune garden plants, Pruning garden plants, how to prune, gardener Bourne End, Marlow
Many gardeners or would be gardeners are intimidated by the prospect of pruning garden plants. It is perhaps the most mis-understood garden maintenance practice. But if you know what the objective is behind it, it becomes much simpler.
Consider first why you are pruning the plant. Then when is best for the plant, distinct from when is best for you. Sometimes the only time to prune is when you have time to do it.
There are several reasons for pruning
Restricting the size of a plant, to avoid overpowering adjacent plants and the landscape.
Removing growth that distracts from the shape, balance or symmetry of the plant.
To remove diseased, dead, or diseased plant tissue, the Three Ds.
Stimulate flowering and/or fruit production of old plants.
Create a desired plant form, like a simple hedge or a more complex espalier.
Direct growth in a particular form to eliminate or prevent problems. For example, reducing high of roses to prevent winter wind rock.
Remove plant parts that obstruct views or visiblity, access, or conflict with structures or utility lines.
Different plants need different pruning
How to prune depends on the plant type. The RHS narrows it down to 13 distinct groups, but you can take a broader and simpler view. Consider first just three categories: broadleaf evergreen, narrowleaf evergreen and deciduous plants. Each type responds differently to pruning, so know the plant type before you begin.
Broadleaf evergreen plants
These have broad, wide, or flat leaves. Shedding of old leaves and the growth of new ones synchronise so that the plant looks like it is never without leaves. Hence the term “evergreen”. Broadleaf evergreen plants include some of the most popular landscape plants. Examples include hollies, ligustrum (privet), photinia (most often Red Robin), elaeagnus, euonymus, azaleas, pyracantha, nandina (chinese or sacred bamboo), gardenia, pittosporum, osmanthus, buxus, camellia, aucuba, mahonia, fatsia, and magnolia.
Smaller leaved plants like Berberis also come into this category.
Broadleaf evergreens have latent buds along the branches and stems that can become a growing bud. A latent bud remains dormant until stimulated into growth. The presence of these special cells allows fairly drastic pruning of these plants without fear of killing them.
There are also dwarf forms with a compact, dense growth habit. These may need little or no pruning to control size or shape. Tip pruning may be used to encourage a thick, well-shaped plant, but can need rejuvenating after a few years. They can be pruned severely (6 to 12 inches from the ground) with satisfactory results. Do this in early spring, before any new growth begins.
But others are substantial vigorous growers in need of annual or twice yearly pruning to control them. Tip pruning or trimming each year controls size or shape and is good practice for fast-growing broadleaf evergreen plants.
Narrowleaf evergreen plants, or Conifers
Conifers are mostly shrubs and trees that will not tolerate severe pruning. The narrowleaf evergreens have tiny, scale-like or needle-like leaves. Many produce a fruit-like cone, which gave the name “conifers”.
Examples include junipers, arborvitae, pine, cedar, spruce and teh controversial Leylandii. These evergreen shrubs need occasional foliage shearing in early spring to control size. they are without the latent buds that broadleafs have, meaning that you cannot prune them as severely. In fact if you cut back beyond the last green shoot you can end up with vast brown areas scarring the plant.
Conifers have a “dead zone”, located on the older portions of the branches of the plant. To avoid the “dead zone”, never remove more than one-third of the foliage. If you remove all the scales or needles with a pruning cut, no new growth will occur on the remaining limb, and drastic pruning of narrow-leaved evergreen plants can kill them.
This is why regular attention is essential. When they get too tall or wide little can be done to reduce them, other than complete removal.
Prune your conifers by removing a portion of the new lush growth, sometimes called the”candle”. Once this growth has matured the buds present on it may not develop and grow. Trimming the tips of new growth, as you do with a hedge trimmer, before it matures can stimulate buds into growth. The effect is to make the face of the hedge fuller and smoother.
Deciduous trees and shrubs have leaves like broadleaf evergreens but shed their leaves in the autumn or winter. They can be pruned hard without fear of killing them, like the broadleaf evergreens. Some common deciduous shrubs include forsythia, spiraea, weigela, lilac, rose, quince, honeysuckle, and hydrangea.
They’ll may need pruning to control the size and shape of the plant. Light to moderate tip pruning encourages thick new growth, resulting in bushy plants. Deciduous plants also may be pruned harder (thinning) or severely (rejuvenation), methods normally used before new growth begins in the spring.
Some different pruning methods
Pruning the tips encourages a thick, well-shaped plant. That is effectively what happens with regular trimming.
Light tip pruning removes only a few inches of stem tips. This method is used to encourage bushier growth as it starts in the spring.
Thinning encourages broadleaf plants to flower and put on strong growth. This method is performed before the new growth begins. Older or weaker branches should be cut back to a lateral branch or completely to the ground.
Shearing – hedge trimming – controls the shape and size of all types of shrubs. Shearing calls for clipping the newest foliage, usually just the surface couple of inches of new growth. Actually, shearing is a type of tip pruning that removes minimal foliage. Broadleaf evergreen hedges and screens are often sheared to promote thick, dense foliage.
The largest leaves of some hedging plants are not easy to trim and maintain a tidy finish. the larger the leaf the further away it should be from scrutiny. For hedges that are more closely observed try to use smaller leaved plants.
Rejuvenation is severe pruning used only on broadleaf evergreens and deciduous plants to control overgrown, leggy, and straggly plants. Use this method of pruning garden plants in early spring before the beginning of new growth. For example, use it for fast growing clump-forming shrubs such as Buddleia and Mahonia. Cut back hard one-third of the oldest limbs each year.
Espalier is the art of training the plant against a wall. Tall walls are best for this method. Pruning may be necessary several times throughout the year to direct the desired shape and form.
Topiary is the art of shaping plants into ornamental forms by careful pruning or trimming. Pruning is required several times during the year to keep them in perfect definition.
The time of year for pruning garden plants is important. Pruning at the wrong time will stimulate new growth, possibly left exposed to early frosts or freezes. It could also remove flower buds that have formed, reducing next year’s flowers. The following guidelines will help you prune your plants at the proper time. Most pruning is for size control, and should be done in late winter through early spring.
Pruning garden plants should take place after the landscape feature of your plant has passed. For spring flowering plants, prune in late spring as the flowering season is ending; this allows for adequate growth during the summer to produce flower buds for the next year. For fall-flowering plants, such as some of the camellias, use tip pruning or thinning method. Prune as the flowering season is ending. Plants with berries should be left until birds have eaten them.
For plants that produce flowers on one-year-old wood (usually those that bloom after June), such as hydrangeas, glossy abelia, and crape myrtle, cut away only those branches with spent flowers or prune (thinning method) in late winter to promote vigorous spring growth.
Prepare your garden for winter what to do to prepare your garden for winter, gardener Bourne End, Marlow
The first frosts have made their mark, leaving all tender bedding and perennials are black and mushy. Here are a few things that must be done now to prepare your garden for winter.
This list of jobs includes lifting tender plants to protect overwinter and mulching those that will be left in situ. You’ll also need to clear the residue of perennial plants that have now died back for winter. And now is the right time to move and replant dormant shrubs. You can also plant new bare root or root ball plants.
Clearing the detritus means the winter framework is left to be enjoyed. Those nagging jobs would otherwise distract you from the winter beauty.
The dahlias and cannas have been hit by frost and need to be cleared, as do thecalla lillies.I have treated them all largely the same, but this year am leaving some cannas in the ground. These will have an initial mulch of grit or gravel. Mulches can be topped up when I do a winter compost mulch of the entire bed. Others will retire to the greenhouse to be kept slightly damp. If the ground looks like it will freeze I might have to remove them all to the greenhouse.
The gravel serves to stop frost penetration but does not keep moisture at the crown, or that is the theory anyway. It also shows me where they are, so when I dig the beds over to remove weeds I don’t stick my fork into them.
I employ a similar tactic when planting bulbs. Just covering the surface where they are planted with gravel helps me to see where they are. It eventually gets turned into the soil and helps with the overall balance and my drive towards perfect soil; eight years working on it and some to go still.
Some bulbs will also benefit from having a little grit or gravel underneath to prevent rotting in damp soils. They need just enough to stop water gathering and rotting the basal plate.
Clearing the decks to prepare your garden for winter
Clearing away the detritus of the autumn will also prepare your garden for winter. That way you may enjoy the structure left behind in the post-perennial period.
Mine is buxus shapes – still forming – and multi-coloured stems of dogwood, under-planted with cyclamen, narcissus and primulas.
Removing the decaying growth also enables the first shoots of spring to be seen more clearly, something we’ll be awaiting with anticipation of warming and longer days. Replacing it later with an even mulch of compost brings a neat background where new growth sings out.
The waste collected of course contributes to the compost heap, continuing the cycle of material grown from compost and returned to it.
I have also cut down my – or more correctly my daughters – banana tree. This will also be left in place with a fleece wrap and wire cage, topped with bubble wrap to prevent water getting at the crown. Now three years old, leaving this plant out is nerve racking. But in the sheltered spot I am hoping it will not just survive but benefit from the southern sun as it rises in spring.