However for perennial and especially biennial plants it’s often a necessary pre condition for flowering – we’ve just been hearing from the pundits in the fruit world that the recent  cold snap  will improve the prospects for bud formation for top fruit (that’s apples to you) and stone fruit (plums, cherries etc.)

As gardeners, we often lose sight of the  way that we are messing with the plant’s natural cycle. If we want leaves (lettuce, spinach etc) we are trying to hold them back from flowering – in fact we get rude about it and call it “bolting” if they manage to have their own way. And if we want them to fruit – beans, tomatoes, squash, we want to push them on as soon as their leaf structure is big enough to give them the push they need.

Cold plays its role in this by acting as a signal to get on with flowering. The technical term for this is vernalisation ( to distinguish it from hibernation I suppose).

It’s kind of like a board game where the aim is to accumulate degree days.  So one degree day is one day spent below a given temperature which varies from plant to plant. 1 day at 6 degrees below is worth 3 days at 2 degrees below. When the critical number is reached then the plants will move onto the next phase in the cycle.  This tends to be a feature of long day plants.

So if you are growing leeks and onions you can do without it because you want the plants to stay vegetative but if you are growing cauliflowers and broccoli you want the cold to get the plants to move on.

So subtle is this science that breeders have produced varieties of cauliflower with different degree day requirements to allow commercial growers to produce a continuous supply from autumn (where they produce florets at the drop of a hat to spring varieties that need a long sojourn in the deep freeze. One trick you might consider for getting uniform curd production is to put the seedlings into the refrigerator to saturate their cold requirement so that they’ve already got their quota. Then you can predict when they are going to flower. Generally about 14 days is enough according to Bleasdale. However for a gardener you might want to stagger the length of time you give them in the fridge.

Spring  Cabbage is generally on a knife edge here. The trick is to get just enough growth. Too little and the plants will be puny. Too much and they’ll bolt as soon as they get enough daylight if they have had a good freezing. Commercial growers manage this by careful control of the sowing date. About 20^th July in the English Midlands is a good bet. And if we have mild winters and autumns – look to your cabbage and autumn sowed onions to bolt.

You can keep track of  degree days by using a thermometer – our soil test and max min thermometers work well for this purpose.

However because it depends on the precise variety and your growing conditions you will need to keep your own records for things that important to you.

Of course degree days matter on the other side by having an effect on how fast plants grow. We’ll look at that shortly.

View across the site to South West showing Mulberry Tree

I’ll keep you up to date as we progress.

If it carries on like this and we don’t get a cold snap then all kinds of things will happen.

Plants that rely on vernalisation and a certain number of cold degree days are going to be thrown out of sync. The alstromeria in the glass houses are still flowering – usually they need a cold snap to take them down to the ground.

Then we are likely to have a higher than usual pest complement in the early spring. We still have flies both in the house and in the packhouse which is unheard of at this time of year. They’re the small ones but even so. So you can probably count on the slugs and bugs getting a head start this year.

However it’s great to enjoy the signs of Spring at Wakehurst place which is just up the road from us here.

Here are a couple of pictures of early buds and flowers taken last thing yesterday afternoon.

January BudsJanuary Flowers

January Flowers

1) Get the annuals out, cut back the perennials and apply a 3 inch mulch of compost.

2) Get new fruit trees in – dig a shallow but wide hole and use the fork to loosen the bottom. Don’t put compost in the hole – other wise the roots will stay in the hole and not go looking for food.  In any case make sure that the graft is about 2-3″ above the eventual ground level. and stake the tree for its first 3 years. However The Intelligent Garden recommends you use a pair of old tights to tie it to the stake – guarantees a bit of movement in the wind without damaging the stem.

3) Divide and move tired, old Rhubarb. The newer, more vigorous growth is on the outside so focus on getting some good strong pieces. Then plant them out with some compost. You will need to be doing this now as you’ll want it to kick in in March/April.

That should keep you out of mischief.  We were really interested in what he had to say as we’re planning a woodland garden round the house to incorporate some permaculture ideas so we’ll let you know how we get on.

It’s an easy and reliable method for propagating deciduous trees, shrubs and climbers. The “season” lasts from now until late winter.

So now that the plants are dormant, you can get on with it but it’s a good idea to avoid periods of severe frost. The best time is just after leaf fall or just before bud-burst in spring.

The cuttings can generally be forgotten about until the following year, as the cut surface undergoes a period of callusing over the winter from which roots will develop in the spring.

How to do it

You can either grow them on outdoors in the ground in a trench or you can grow them on in containers .Some, dogwoods for example will benefit from protection with cloches or coldframe.

Hardwood cuttings grown on outdoors

• Select vigorous healthy shoots from this year’s growth.
• Remove the soft tip growth.
• Cut into sections 15-30cm (6-12in) long, cutting cleanly above a bud at the top, with a sloping cut to shed water and as a reminder which end is the top.
• Cut straight across at the base below a bud or pair of buds and dip the lower cut end into rooting powder or Root!t gel.
• Prepare a trench outdoors in a sheltered site with well-drained soil.
• Dig in a bucketful of garden compost or other organic matter every square metre or yard and put a layer of sand into the base..
• Put the cuttings into the ground or pot with two-thirds below the surface.The roots will form along the stem. A few buds remain above the ground to allow the plant to grow away in spring.
• Where a single stemmed plant is aimed for, such as Populus or gooseberry,  leave only one bud above ground.
• Put the cuttings in at 10-15cm (4-6in) spacing with 40cm (16in) between trenches.
• Keep an eye on the trenches for frosts and firm up afterwards if necessary.
• Leave them there until next autumn to make sure they get established through dry periods next summer

If you have only a few plants then put them into containers of gritty potting medium and keep them in an unheated greenhouse until next autumn making sure they don’t dry out.

Alternatively you can over winter plants like Cornus and Laburnum in pots and then plant them out as above  in the spring into a trench firming the soil round the cuttings.

This technique will work for

• Most deciduous shrubs like Abelia, Deutzia, Buddleja (butterfly bush), Cornus (dogwood), Forsythia, Philadelphus (mock orange) Ribes (flowering currant), Rosa (rose), and Symphoricarpos and viburnums.
• Climbers like: Vitis (vines), Lonicera (honeysuckle), Jasminum, and Parthenocissus.
• Fruit, including: gooseberries, black, red and white currants as well as  fig and mulberry.
• Trees, including: Platanus (plane), Populus (poplars) and Salix (willow)

Finally now is the time to take evergreen  cuttings like  Cotoneaster, Ilex (holly), Ligustrum (privet), Skimmia. But treat these like semi-ripe cuttings as we discussed a couple of posts ago..

The most interesting presentation of the lot was one on the 3 stages of GM from Professor Sir David Baulcombe. I’ve tended to be a GM sceptic as it has appeared that the amount of spraying hasn’t gone down on the round-up ready strand, yields haven’t gone up, farmers have become more dependent and the companies that produce these products have created a monoculture with the IP owned by them which is bad  for food security on both counts.

If my time as a biologist taught me anything it’s that if you routinely subject the environment to pest killers – whether it’s round-up or antibiotics you end up with resistant organisms. MRSA, avian flu, round up resistant super weeds.

However. In the Professor’s extremely interesting talk he identified 3 stages of GM.

Phase one is the current generation which rests on two main techniques – the insertion of a round-up resistant gene into Soya, rapeseed, maize, alfalfa and sugar beet and the insertion of the bT gene which produces an anti-corn borer toxin into maize and cotton.

What he called the second phase of GM comes about because gene sequencing techniques have advanced to the point that any genome can be sequenced in a day at a trivial cost for a business.

Apologists for GM have always insisted that it’s not different from traditional plant breeding.

For Generation one plants where transgenic modification has occurred with bacterial genes being inserted into higher plants this is of course nonsense. However with generation 2 we have the possibility of real cis genic (i.e. genes from the same organism) being used and the statement becomes a much more accurate reflection of reality.

You can identify visible markers for specific genes that you want and breed for those. Further by being able to sequence you can select directly for the genes themselves without having to wait for the plant itself to grow to maturity. Some useful things could be done here which would actually improve the plant itself – something that the original excursions into round up ready and bT didn’t do. Things like improving drought resistance, increasing the number of root hairs, additional metabolic pathways etc.

This really is an acceleration of natural process. It has the advantage that you don’t lose the original characteristics of the plant which could be reinserted later. I could well be convinced that this could be a way forward if it improved flavour, yield and truly produced better plants.

In Generation 3 the Professor believes we could create whole new organisms. Personally I would be wary of this although a perennial nitrogen fixing wheat would be pretty cool.

The chances of ending up somewhere we might not want to be seem quite strong particularly regarding the notorious elasticity of the US regulatory authorities when confronted by a multi-national in full cry. The existing evidence of genetic flow and super weeds that we already have to deal with seem to me to argue in favour of caution here.

Interestingly the Professor despite being very pro GM techniques felt that the need for scientific management of crops, the issues of genetic flow and the existing IP regime were issues that really need to be addressed if these techniques are to be truly beneficial to the quest for food security. I rather think he’s right.

He gave a great summary and I hope I’ve done it justice. At the very least it was a welcome change to listen to a talk on this topic that generated more light than heat.

As a finale there was a very interesting discussion afterward between the Professor and one of the more organic farmers there. It’s available on You-Tube and you can see it here

Awooga Awooga - vine weevil alert

This cheekly little chap is a vine weevil. Those of you who follow Gardener’s World may remember that Monty Don was warning you about these last week. If you don’t nobble them now they’ll keep on chomping away at your plants and their roots all through the winter so that by the spring they’ll be feeling sorry for themselves.

The same is alas true for lawn as Mr Vine Weevils mates,  the leather jacket and chafer bug gangs are busy munching away encouraged by an almost supernaturally dry autmn.

This one was swanning about as bold as brass in our nursery so he was duly measured by the management and turned into a sales pitch.

Our sister company, Ladybird Plantcare, sells the nematodes that stop these little blighters in their tracks so that you won’t have to endure the spectacle of swathes being  cut through your precious plants next summer by the adults that these chaps will turn into.  Orders received by midday Monday will be shipped Wednesday afternoon. Visit us here to find out more.

So have  look and see if there’s anyone looking like this at large in your Garden and if so give us a call

Rooting Gel

This is the time of the year for reproducing your plants. Nature plants her seeds in the autumn after all – the ground is warm and the plants are still awake.

The team on Gardener’s World have been focusing, however on vegetative reproduction. Taking rose cuttings, dividing perennials etc. so I thought I’d put together a summary for you.

At this time of year we’re looking mainly at semi-ripe and hardwood cuttings. The softwood cuttings on this years growth are taken in late Spring.

The reason that we want to make cuttings is that we can greatly expand the number of plants we have in our garden inexpensively. The reason that we can make cuttings is that thanks to the wonders of nature a plant knows which way up it is.  Plants produce Auxins at the apical tip. These plant hormones feed down the stem and ensure that the apical bud continues to grow by inhibiting the growth of lateral buds. That’s why pruning results in a bushier plant. It will promote rooting if its concentration is greater than the cytokinin hormones that are generated in the roots. If they are about the same then it will favour production of xylem – the woody tubules that the plant uses for hoisting water from the ground to the leaves.

So – to make a cutting we want to retain the apical bud if possible or at least cut the plant above a node. At the bottom of the cutting we need to make sure that the auxin level is high – which is why people use rooting powder or a purpose made gel like Root!t. Other things that cuttings like is a high humidity to keep the (turgor) pressure in the leaves up and a means of sealing the bottom cut so that air doesn’t get into it. Left to its own devices the plant can plug its own wounds using a compound called callose which is like cellulose only different (believe it or not that’s what my D Phil was about but I won’t bore you with it here).  However if you use a gel like Root!t it will help the sealing process.

One way of keeping the humidity up is to use a propagator – either a simple one or a heated one. If you are working on a larger scale you might consider a mister. Here in the Glasshouses we create a tent with polythene over the propagation bench. Or you can use polythene bags at a pinch.

It’s important to keep everything clean and to use sharp knives and scalpels. You need to keep them moist and if possible cut them first thing in the morning (allowing for frosts of course). This will help the plant not to wilt too much. You are going to injure it so you need to give it the best chance you can to recover.

So what do you do?

You take different types of cuttings at different times of the year. These are known as softwood cuttings which you would take in Spring, semi-ripe cuttings taken in August – mid October and Hardwood cuttings taken after the leaves have fallen.

Semi Ripe Cuttings

Taking Cuttings

In the second half of this  article I’m going to cover semi-ripe cuttings since we’re just about in time to do these followed by hardwood cuttings in the next article.  The softwood ones will be the third in the series

However the absolute basics of cutting are

You cut below a bud horizontally. For best results cut with scissors or secateurs first to seal the cut and again with a really sharp knife just before you pot it. This cut is square. At the top end you either include the apical leaves and between 2 and 4 nodes depending on the plant or you make a sloping cut above a bud. You keep the cuttings moist until its time to pot them. Then you seal the bottom with Root!t Gel which contains auxins and then keep them moist and sheltered over the winter.

Semi-ripe cuttings are an easy way to propagate a wide range of hardy climbers, herbs, ground-cover plants, shrubs and trees – especially evergreens – without the need of special equipment or skills. This technique is suitable for berry fruits, Ceanothus, Forsythia and Philadelphus.

So before the leaves drop off – now is the time to get organised.  We have maybe a 10-14 day window before we get a frost severe enough to start the process in earnest. Our Mulberry tree last year dropped the lot overnight.

This is the RHS list of plant suitable for semi-ripe cuttings.

Groundcover – Lonicera pileata, periwinkle, Rubus tricolor and calycinoides.

Climbers:  ivy, passion flower, Solanum and Trachelospermum

Evergreen shrubs : Artemisia, Berberis, Brachyglottis, Camellia, Ceanothus, Choisya, Cistus, Convolvulus cneorum, Erica, Hebe, Fatsia, Mahonia and Viburnum.

Hedge plants: box, cherry laurel, Escallonia, holly, Lonicera nitida, Portuguese laurel and privet.

Perennial Herbs : bay, hyssop, lavender, rosemary, rue, sage and thyme.

Trees : Holly, Magnolia grandiflora, evergreen conifers.

What to do.

Take the cuttings from this season’s growth. The base of the cutting should be hard, while the tip is still soft. This material is available in late summer until mid-autumn.

Select healthy shoots free from pests and diseases that are more horizontal in habit with short internodes (gaps between the leaves). You can encourage these by pruning some plants really hard in the spring.

Types of semi-ripe cuttings:

• Standard:  cut just below a leaf to leave a cutting of 10-15cm.
• Heel: (where the cutting is pulled away with a piece of the stem) suitable for – Ceanothus and Berberis and Roses.
• Basal: cut the shoot at its base. Suitable for Broom.
• Mallet: Plant a leaf as a cutting, burying it with a piece of stem. Used for Mahonia

Taking a basic semi-ripe cutting

• Use this season’s growth and remove using sharp secateurs.  This will seal the cut
• Put in a plastic bag straight away. – pot the cuttings within 12 hours.
• Trim to 10-15cm (4-6in) in length, cutting just below a leaf node. Next, remove the lowest leaves and the soft tips. Leave about four leaves. Cut the leaves in half to reduce water loss if they are big.
• Dip the bottom of the cutting in Root!t gel, ensuring that the cut is well covered. For difficult-to-root shrubs, such as Magnolia grandiflora, try ‘wounding’. This is the removal of Insert the cuttings into suitably-sized containers filled with 50 per cent free-draining potting compost and 50 per cent sharp sand or perlite. Water well and allow to drain.  Alternatively use purpose made plugs like those in the root!t range.
• Put in a greenhouse. They need to be warm and light but out of direct sun.  They need to be kept damp but not waterlogged. Autumn cuttings benefit from a heated propagator like the Stewart ones.

If the plants are hardy you can just put them straight into a spade cut like Monty Don did on Gardener’s world and leave them under a cloche for the winter.

Next post  on the subject will deal with Hardwood cuttings

Permaculture Garden

As I mentioned in the last post, I was reading Graham’s Permaculture Garden while I was on Holiday.

In over 40 years of Gardening I’ve read lots of books and there aren’t many authors that really impress me but I think Graham has to join Geoff Hamilton and Ethelind Fearon on the podium.

It’s a concise and practical review of how permaculture could be applied to a normal garden. He covers all the usual permaculture ideas about doing more with less, grouping things in zones to save energy and to work towards a woodland garden which involves a sensible progression rather than a rotation to increase the diversity of the space. He covers layering and stacking, the use of swales along the contour to facilitate passive irrigation, the benefits of how to make use of the edge effect and the benefits of using perennial vegetables rather than annuals in a no dig progression.

The best thing is that it has a series of easy to execute 1 day projects including containers on concrete, developing a tree garden, creating a grey water reed bet and the ominous sounding German Mound.

Best of all he tells you in explicit detail how to turn a lawn into potatoes by spreading cardboard round the dripline of a handy tree and covering it in compost. Put the potatoes in, follow up with beans over the winter and bodge in some rasp canes the following autumn and your on your way to your very own forest garden.

Watch this space.

btw you can buy his book here.

As it happens we’ve had a couple of heavy duty earthworks around the house here over the last couple of years. Stage one was to remove the swimming pool and creating a platform at the back of the house. All of the soil was deposited in a “bank” ahead of phase 2 which was the excavation of the rainwater harvesting reservoir which has been done this year.

We’ve managed no net movement of soil on or off site but as you might imagine we’ve surfaced quite a lot of topsoil and by May this year we had a lot of bare earth. Other than chucking some grass seed at it we’ve not done a lot.

However on idly leafing through the permaculture books I discovered that the first thing that happens is that weeds act to cover the ground particularly things like docks that bring up potassium from deep down via their taproots.

And the second thing that happens is that leguminous plants invade the space and start fixing nitrogen.

This repair of the ground allows other species to get going and eventually re-create the whole plant ecosystem

Well I can honestly report that on this year’s lot there’s been a pitch invasion of docks and at the back where the swimming pool came out 18 months ago it’s stiff with clover. Both of these happy events have been organised by nature with no input from me at all.

So while I’ve been on holiday I’ve been avidly reading David Bell’s book the permaculture garden and am busily planning a forest garden round the house for a permanent supply of fruit.

I’ll let you know how I get on.