Planting up the main succulent bank.

Building the main succulent rockery has been a lot of physical lugging or rock, soil and gravel. Monday saw the final large delivery of soil and gravel, time to enlist the family for one final push. In the morning the bed was set out ready, extra blocks had been added over the weekend to build up the end so it was ready to go.

The vertical posts had also been added continuing the wave from the side garden.  It was interesting having both the oldest nephew and niece around, they are really getting into gardening; not just the plants but the design as well and there were several discussions about why things were going in certain locations.

By lunch the plants were going in and the biggest rocks were in place.

Then it was just a matter of selecting the best rocks to create a more terraced look.

The gravel ran out before the entire bed was covered, but as the front row has to be finished it's no disaster.

Now the real fun can begin. With most of the big plants in, I can start to see the gaps and where all the bonus interest can be added. every time I look around it I see crevices in rocks that I can see being filled with some choice alpine.

The backbone is there and will fill out over the next few years, but what will really set everything off is the other plants that are not noticeable at first, or that bring colour at different points of the year.

There are so many good corners, gaps, hidden spots I am going to be able to add a lot more plants than expected. There is no rush to do this; I have some plants ready, other gaps will be an opportunity to buy one of the plants off my must have list. Hopefully I will be able to restrain from planting any old plant, to fill the spaces with those rare or special varieties.

Lots of new views to discover

The agave x nigra didn't seem to mind being in pots, the root balls were really strong and there are pups on each plant.  They look good and blue against the rocks which wasn't planned but one of those happy coincidences.

One of my favourite aspects to the bed is the different view you get when sitting on the wall at the table.  It's nice to look down on the plants while also being able to touch them

Plenty of space in there for some litte (and not so little) gems.

There is still a lot of work to do to get it looking how I want, but the main physical stuff is done with the fun bits to go. 

The area around the patio is almost finished, or at least it's looking like a garden.  At some point I am going to have to buy some non-spikey plants to fill the beds along the fence. I'm not going to have an excuse to delay it much longer.

A very strange winter

Many people will wonder why the UK has so many problems given it has mild winters and limited rain fall. In pure numbers this is true; I expect only one or two lows of -8c a year, maybe 2 - 4 days with snow on the ground, and in terms of rainfall London only gets on average around 600mm a year. Compare this to many parts of the USA and you would think London wouldn't have problems.

Last summer and this winter have highlighted exactly what sets the UK apart; our weather does not stick to seasonal patterns as would be expected.  Most of the world have a colder "winter" a warmer "summer" and period of change between.  It is with great envy that I read blogs from the USA in which it is "declared that summer is here" and that is it, the next few months are filled with posts about sun, and heat.  While we do not get extreme cold, or extreme wet, we get more constant cold and wet than other places.  We don't get massive thunderstorms, but days or weeks of light rain. The hottest month of the year can almost be any month between March - September.  Last year was an extreme example, we had a drought from January - May and then floods for the rest of the summer. I understand it is the joy of being a small island.

For me, the lack of an extended period of heat over summer not only reduces growth but also means the plants are less able to cope with winter cold. It can also make this time of year more than a little depressing with week after week of cold and damp (not proper rain). In some respects we have had a very mild winter in London, no real cold and only one period of snow which did not stay around for long.  But then it has also not warmed up as it should do and March has been one of the coldest on record.  So it is a real treat to have had two whole days with no rain and even periods of sun.  Today was the first day of the year it has been warm enough to spend any real time in the garden and so I made the most of it.

Having dug up the dry bed I was concerned that the plants would suffer in pots.  Along with the agaves and yuccas a few of the other plants were removed, including this eremurus stenophyllus. So I was please to find not only new shoots, but more than previous years. It does not seem to mind being in the pot.

So with some sun, and new shoots I could almost believe that we may finally be moving out of winter. Now if only we could move quickly into a nice warm summer.

The hardy succulent garden: Aloes

My dream succulent garden is full of aloes; from the small rosettes to the branching tree forms.  It is difficult to imagine a true succulent garden with aloes, which makes writing this post all the more difficult. I often read posts by people saying which plants they have tried and almost without fail these posts tend turn out to be from people with very mild winters.  The choice of aloes for UK is pretty much limited to 3 plants if we are dropping down to our -10C (or even below -7C).

1) Aloe striatula. This is the most interesting hardy aloe for the UK.  It grows quickly, even in the UK, and the use of tops cuts can not only increase stock, but force it to form a good clump.  It is a fairly reliable flowerer, although I have found flowers depend on heat in spring, other wise they either don't appear or are small.  A few years back we thought they are relatively bullet proof, sadly the winter of 2010/11 proved otherwise.  They are however root hardy even in bad winters and plants seem to come back strongly.

2) Aloe aristrata. By far the hardiest of the aloes, but also one of the less interesting.  Most people tend to think of them as alpines not aloes.  There are a few different forms, mainly relating to size. I saw a monster form last week and was luck enough to be give an offset to try in my dry bed.  They form good clumps and flower every year with problems. 

3) Aloe polyphylla. The most interesting almost hardy aloe. Out of the three plants mentioned here, this is my favourite.  Also known as the spiral aloe, the spirals can either go left or right and it gets to a decent size.  The flowers are the most imposing of the three. So why is it not in position 1?  The reason is that it is a pain to grow;  to much water, too little water, anything in the crown will all cause the plant to fail.  It does require more water than other aloes to grow and even hates drying out for too long in winter.  You must keep the crown free of debris if you want this plant to survive, so planting on a slope seems to work best for this plant.  All of these factors mean that although the cold is not a real problem having an un-protected plant in the ground can be a challenge.  Simple rain shelters seem enough for more mature plants, ensuring that you don't get snow in the crown.  Even this may not be enough for these fussy plants,  and you can expect to loose some while you figure out the conditions that suit them in your garden, (I lost my first 3 and it became a bit of a personal challenge to grow this one). If you want proof that they flower in the UK, then Clarke Brunt's website is the place to look.  

Photo from Clarke Brunt's website

That is it I am very sorry to say.  There are a few others that people have reported as surviving for them; a. brevifolia, a. saponaria and a. cosmo are the ones I hear about most. None seem reliable and more seem to die than survive. I do have a few that are fine in my cold frame, but given this is about plants in the ground, that is no help.

I can't finish without mentioning aloe hercules.  There are some suggestions this one may have some cold tolerance, but as yet there are so few in the UK that none have been tested.  Most likely it will be years before anyone has one to test outside. But a hardy tree aloe would be the ultimate and you have to have something to dream of.

The hardy succulent garden: Agaves

Time for some plants.  The idea is to select the 3 best of plants in each group: agaves, aloes, yuccas and echeverias.  As a recap, all the selected plants should be hardy down to -10C and require minimal protection. This will be easier in some groups than others, so I thought I would start with an easier one, the agaves.

1) Agave parryi. You can't select hardy agaves without mentioning this plant, with the plus of different forms to select from.  You can chose from wide or narrow leaf, colours from green to pale blue, and different size and colour teeth. These are two of mine which show some of the differences.

Most seem to be hardy when mature, but some seem to cope better when small than others. When looking for plants, it is always worth see if you can get a pup off a plant that is already growing outside.  If you are not sure give it protection the first year, so it has time to get established. A simple plastic cloche over the plants to keep the worst of the rain and snow off should be more than enough for this plant.  For my larger plants shown above I simply cover with fleece to keep the snow out of the crown. The plants do not need this to survive, but it keeps them in top condition. My favourite form is a. parryi HK1684, not a very attractive name but the plant is a good blue colour and has the best dark red teeth.

This one was a little small to be planted, but it has grown a lot and is now getting to the size where I would be happy to plant it out.  To get it ready it is left outside over winter but kept dry. I will probably repeat this for one more year and then plant it next year.  In case you are wondering, given that you often see the variegated versions, they seem just as cold tolerant even from a small size.  I have not tested one planted yet, but again kept dry they get you through without problems.  Whichever variety you go for you will no doubt end up with a lovely clump as they pup quite freely.

2) Agave bracteosa. Not the most popular, some say due to the fact it doesn't look like a proper agave, but very hardy from a small size.   I don't even bother to fleece mine before snow and it never even marks, maybe because the leaves are thinner and more leathery.  While it looks like it doesn't have any teeth, the edges to the leaves are sharp and give similar to paper cuts.  I think this plant is actually a safer bet than parryi and I have it is a shame it is not more popular.

There is only one normal form, although there are a couple of variegates.  The most common is a. bracteosa 'Monterrey Frost', these are so expensive and hard to come by in the UK there is no way I would risk mine outside.  I am jealous when I see photos form the USA where these now seem to have even made it into nurseries in bulk.  Hopefully at some point someone will let me know if theirs copes with snow the same way as normal form.

3) Agave montana. If I was only going to select three agaves, then a. montana would have to be one as it is the one that grows best in wetter climates.  There was a lot of hype about this plant when it first came onto the market, the fact that it grows at high altitude in or on the edge of forest.  Two bad winters in the UK and lot of people are now less impressed with this plant.   I think they were being a little harsh, OK it is not the super agave we all hoped for, but part of the problem is people planting tiny plants. This is one that grows into its winter hardiness. In the UK I think plants needs to be at least 30cm across to be fully hardy.  Once they get to that size they seem to have little problem with our wet and cold.  With small plants, I find just keeping them dry is enough the cold is not the problem.  Then with larger plants I just keep snow out of the crown.

There are a few other agaves are equally hardy (which I'll come to in a bit), but this one made it into the top three because of its lovely red spines and its very structural form.  If a. bracteosa is not agave enough for you, then a. montana is the plant for you.  Sadly it is unlikely to offset, to you have to plant your own clumps.  Leave plenty of space though as they fill out very quickly even in the UK.

So there are my top three hardy agaves. To be honest there are a few others, that could be in the list (probably in the place of a. parryi as the least interesting of the three).  Here are some of the best of the rest:

Agave x nigra.  A very hardy plant and well worth a place

Agave filifera. I was surprised that this one copes in my dry bed.  I put a cloche over my larger one as I really want to keep it pristine.

And some the jury is still out on, they should be OK although can be very variable, but well worth space if especially if you are going to use rain covers.

Agave gentryi, a close relation to a. montana.  This is famous for the teeth on the leaf margin.  There is a form called 'Jaws' due to having huge teeth. These have done OK for me with on the snow kept out of the crown.

Agave weberi.  Another of the toothless forms, this one gets good and big.  There is a lovely wide leaved version which is worth tracking down if you can find it.

Agave victoria reginae. This is another that has really surprised me, I have two planted out, one with a rain cover and one without and while the rain cover has helped, it does not seem to have made as much of a difference as I expected.   These are slow at the best of times anyway, so it is difficult to know if they are struggling or not.

Agave mitis.  Used to be a. celsii and you often still find it sold as such.  Quite a soft leaf and is a slug magnet.  Damaged leaves will rot come winter, but if you can keep the slugs away it is fine with just fleece to keep the snow off. There is a gorgeous blue form which is well worth looking out for as a specimen plant, although don't plant it as the rain will spoil the look.

Agave salmiana var. ferox. A good chunky plant. There are reports this is hardy, but mine struggle without rain covers and were killed with snow in the crown.  It is worth a go with rain cover, but I don't think it is reliable without them.

So those are the agaves, as you can tell, I think there will be more than three varieties in the bed.  Please feel free to post your top 3 hardy agaves.

The hardy succulent garden: structure

Design is an important part of creating any garden, more so when trying to create a hardy succulent area.  I tend to do lots of drawings of the area, measure it up, work out how much sun it will get and finally plan the planting.

One key part of this is thinking about the planting medium and the physical structure. When it comes to growing succulents in the UK the mantra is "drainage, drainage, drainage".  It is not enough to simply add gravel to the soil, or even replace all the soil with gravel. There is a big difference between a gravel garden planted with local plants or alpines, and trying to grow succulents from much warmer areas. If you want a truly versatile dry bed then it has to be raised, either by building a wall around the whole thing or using a rockery. There are two reasons for this, the first being drainage.  Raising the bed above ground means that if the planting medium is free draining, any water will run straight through and out of the bottom.

The second advantage is that in raising the bed up you have an opportunity to introduce a heat sink.  These are increasingly being used in green house and even house design, but are not widely mentioned when it comes to the rest of the garden. I am sure most people recognise that a large rock on the surface will store heat during the day slowly releasing it over night. Multiply that up with a pile of rocks and you have a heat sink which may be the difference between life and death for some plants. In my current bed, I used all the dug up concrete to raise the levels and filled gaps with gravel This extra mass forms the base of my heat sink and I suspect maybe one reason I can plant some the plants in my dry bed.   The height and heat sink were increased further with a more sculptural top layer of large rocks, forming the pockets into which the plants where placed.

I am already considering options for my next garden, do I want brick or stone walls, railway sleepers, or perhaps build only the back wall and then slope the bed down to ground level at the front. Then what stones do I want to use? I like the river boulders I have in my current bed, but I have seen some amazing succulent beds using volcanic rocks and darker stones. Finally do I want to include any soil at all? My current front bed is almost pure gravel, but this slows growth down and having a way I can include soil in some location without it washing away would probably be helpful to some plants.

It's only once I get into the new garden and see the space; what shapes I want, and how the succulent bed will fit in with the rest of the space, that I will be able to finalise exactly which method I use. Whatever I end up doing, all the succulent beds will be raised to some degree and will make the most of heat sinks wherever possible.

I should give one warning though.  Should you ever come to move you had better hope that the next person wants a dry bed, other wise they are going to have to move all that material back out again!

The hardy succulent garden: Climate

What with digging up the dry bed allowing me to closely examine the plants and hoping the next house will have a larger garden, I have been thinking about the hardy succulent garden. With this in mind I thought I would do a series of posts on the topic. A lot of it will be in planing for the next garden; thinking how to build the beds, what to plant and what winter protection (if any) to use.

So what do I mean by a hardy succulent garden?  Firstly the majority of plants have to be planted all year, not just sunk and dug up before winter.  For me the plants will mainly fit into the groups of agaves, aloes, echeverias, yuccas, with a few other plants both as features and as fillers. Finally winter protection should be kept to a minimum and should be about keeping plants in pristine condition not about survival.

For this first post it seems sensible to look at my climate. Living on the edge of London my winters are not that bad, -10C (14F) would be my absolute minimum. Although we do get 2 - 3 snow events a year, they usually only last a day or so and it is very unusual for snow to stay around for a week. Sadly when this snow is wet and is prone to melt and re-freeze and this does more damage than the drier snow other areas of Europe gets. Perhaps as important are the summers, you can get away with a lot more if you have long hot summers.  Our summers are often neither of these and it can seem to rain as much in summer as in winter. While that is not the case, we do not get the extended hot periods that these plants would really like.

I'm not sure exactly how the series will pan out.  I'm thinking of a post on the planting material / bed structure. Then one on each group of plants and finally one on winter protection. I have no idea if it will be useful for me or others, but it will at least give me something to do until I can actually get on with the new garden.