Help with creating rockery please

[Andy87]

Hi all,

I am thinking of adding another feature to our garden - a rockery. The site is a flat one, so how can I create a sloping effect on the rockery?

I had thought of creating a step effect with larger "ornamental" rocks. So for the highest step, there would be, say, five large ornamental rocks beneath it. The next step would have four rocks and so on. The actual steps visible would have the plants on them as well as other smaller rocks to add variety. Has anyone tried this?

Many thanks,

Andy.

[Cotham Marble]

Originally Posted by Andy87

Hi all,

I am thinking of adding another feature to our garden - a rockery. The site is a flat one, so how can I create a sloping effect on the rockery?

I had thought of creating a step effect with larger "ornamental" rocks. So for the highest step, there would be, say, five large ornamental rocks beneath it. The next step would have four rocks and so on. The actual steps visible would have the plants on them as well as other smaller rocks to add variety. Has anyone tried this?
Many thanks, Andy.

I can see the logic of your approach, but there are some questions that would be helpful to have answers to before anyone can answer you helpfully:

1. Is the rockery simply a way of adding 'contours' to the garden, or is it because you actually want a rockery ?

2. What planting scheme do you have in mind ? Are you looking at specimen alpine plants or do just want to create an overall effect ? Or something else ? Is it to have wildlife value ?

3. What is the soil type, garden aspect, sun, shade etc.

4. Is this your first rockery ? Are you happy about the volumes of soil/rock that are involved ? A rockery just one metre square, built as you suggest would involve moving the best part of a ton of material.

5. In the absence of any of the above info my advice would be to read some books - a visit to the library might be worthwhile.

CM

[Andy87]

Hi CM,

1. I actually want a rockery.
2. The plan is to have tall plants at the top, getting shorter as they go down the rockery. So no specific species in mind at this point in time. I intend to have rocks and little pools for frogs!
3. I wouldn't like to say for sure what the soil type is. Would hazard a guess at clay. The site would get around 4 hours of sun during the day.
4. It would be *my* first rockery. We used to have one, but I am too young to remember it properly. A lot of the rocks are simply in a river at the bottom of the garden. How could I reduce the volume of rocks and soil involved? Is there another way of constructing it?

Andy.

[Cotham Marble]

Originally Posted by Andy87

Hi CM,

1. I actually want a rockery.
2. The plan is to have tall plants at the top, getting shorter as they go down the rockery. So no specific species in mind at this point in time. I intend to have rocks and little pools for frogs!
3. I wouldn't like to say for sure what the soil type is. Would hazard a guess at clay. The site would get around 4 hours of sun during the day.
4. It would be *my* first rockery. We used to have one, but I am too young to remember it properly. A lot of the rocks are simply in a river at the bottom of the garden. How could I reduce the volume of rocks and soil involved? Is there another way of constructing it? Andy.

Andy,
Firstly the question of the rocks from the river - it may be that your property does include ownership of part of the river bed, however even if that is the case removal of any quantity of material may cause instability in the bank and result in impeded river flow. With increased concern about flooding and potential financial claims that follow you should be very clear about what the consequences of removing material actually are before proceeding.

The purpose of creating a rockery usually falls into three main categories - 1) to provide an environment for plants that the garden would not otherwise sustain e.g Alpines 2) to provide elevation of part of the garden for visual effect 3) to provide hard landscaping (rocks, scree etc) for visual effect.

The volume of material needed is to an extent dependent on what the purposes of the rockery are - but the very nature of the project requires moving, and often importing to the garden, large quanties of soil/rock.

I would suggest this is the kind of project that needs an allocation of time based on 90% planning and 10% actual work. What you have in mind may work but I really think you need to research in detail before attempting something that simply may not work. Certainly it is a project beyond the capacity of the ad hoc advice that can be given on this forum.

Good luck.

CM

[Jez]

Sorry to butt in! Can I ask a question here?

I'd like to know what a ton weight would be in Kilos! Anyone know?

Sorry to hijack the thread

[Tursiops2]

Originally Posted by Jez

Sorry to butt in! Can I ask a question here?

I'd like to know what a ton weight would be in Kilos! Anyone know?

Sorry to hijack the thread

Hi Jez
1 ton = 1016 Kg

useful conversion tables here:
Online conversion of weights and measures, measurement conversion.

T2

[Jez]

Originally Posted by Cotham Marble

A rockery just one metre square, built as you suggest would involve moving the best part of a ton of material.

Originally Posted by Tursiops2

Hi Jez
1 ton = 1016 Kg

So that's just under the equivalent of shifting 20 big bags of spuds per square meter. Just so I get it!

[Cotham Marble]

Originally Posted by Jez

So that's just under the equivalent of shifting 20 big bags of spuds per square meter. Just so I get it!

the metric tonne and imperial ton are close enough for most purposes of rough estimating. A cubic metre of water weighs one tonne - if you know the specific gravity (its density relative to water) of a material, it is then easy to work out what a given volume weighs and vice versa.

Very roughly - soil can be calculated at an SG of 2 - so a cubic metre weighs about two tonnes. Rock is much more variable anything from 3 to 6 SG but in the UK most will be around 4 to 5 so a cubic metre might weigh five tones. I used to know all the equivalents in cubic yards and hundred weights - but life's too short to hang on to that stuff !

Not sure about bags of potatoes - do you buy them by 50Kg/Cwt sack ? Cement used to be a good reference - exactly 20 sacks to an imperial ton.

I've certainly shifted several tons of soil in a day in my youth and I've known blokes who've claimed to have hand mixed over ten tons of concrete in a day, so rockery building isn't at the limits of human capability - but I think most people would be surprised just how much material can be involved. More Time Team than Gardener's World.

CM

[Jez]

For some reason I worked out 20 bags of spuds in lbs when i do my spud math in kilos= 40 bags of spuds! So double the load unless you have the soil already there to work with?

[Cotham Marble]

Originally Posted by Jez

40 bags of spuds! So double the load unless you have the soil already there to work with?

In most cases (depending on planting scheme) the recommended approach would be to create an 'ideal soil', as once built the only way of adding nutrients and soil conditioners is by top dressing and possiby some shallow digging.

So while using the native soil may be possible (no chance if you've got pure clay and want to grow alpines for example) may be possible, it still has to be lifted and cleaned of all perennial weeds (bindweed in a rockery ?) and compost or other organic material, plus a free draining material - grit or similar also added. For an alpine orientated rockery the traditional mix is thirds of top spit, organic material and grit.

Of course one can just get a few lumps of stone and set them in an existing bed as landscape features, but that does not really count as a 'rockery' in the formal sense.

CM