Helen's Garden Renovation Project

Yesterday I emptied the temporary pond. Unfortunately there were still some newt tadpoles in the water. I managed to save some of them and transferred them to the shallow pond. I also encountered three adult frogs, but no adult newts. I thought about whether I wanted pond snails in the shallow pond, and I decided that I had done all right with them so far so I would put them in. I don’t know whether they will crawl up the wall and get into the raised pond, but I don’t suppose they will do any harm if they do.

I pulled the pond liner partly out of the pond because rain was forecast later and I didn’t want the pond to fill up again. Then I put a few bricks and other things in the hole to help frogs get out if they should jump in without noticing that all the water had gone.

After emptying the temporary pond

Today we had a fine, dry day and I decided it was a good day for shredding things, so I cut bits off the bay tree and shredded them. I also moved the compost bins out of the way. I have been advertising the compost bins in Sainsbury’s and have managed to get rid of one out of the three I had left. Digging up the bay tree may be a harder job than digging up the Leylandii. It may take me more than one session. It will also be a big job to fill the pond. I had forgotten how deep it was.

The bay tree after pruning

The level of water in the shallow pond continues to fall. I think it must be leaking from more than one place. I am thinking of various ideas about what to do. One option is to remove the liner entirely and replace it with a new liner that comes up along the back of the edging blocks. I don’t know whether this will affect the stablity of the edging blocks. Another possibility is to dig up the soil at the back of the two edges of the pond that don’t butt onto the patio, and then leave it, and see which bits become damp after rainfall. I would hope this would tell me whether there are particular places where the pond is leaking from. Taking up the patio to observe the edge that butts onto the patio would be drastic, but again could be done. However, I am going to leave this to be done after completion of the main project. I feel more strongly than ever it is time to bring this ship into the shore, and throw away the oars. Forever. I have had enough of the portable herbaceous border. I want a proper garden again.

So, I am still planning to get the right hand part of the garden finished this winter if the weather is unexceptional. I should be able to get the bay tree dug up, the pond filled in and the path taken up by the end of October. I can then use the rubble from the path foundations for the stepping stones in November, and also work out the layout for the section. Then in December I can get quotes for any work that I cannot do myself, and have the work done in January. Then order lots of soil for the lawn, get it level and fertilised, and sow the lawn seed in April. And if you believe this will happen without any further slippage, you have much more faith in human nature and circumstances than I have.

After I had finished waterproofing the shallow pond and mending the water butts, we had lots and lots of rainfall, which I was very pleased about because it meant that my repairs could be thoroughly tested. I was only partly pleased about the results, though. One of the water butts appears to have been completely mended, with no signs of any leaks. The other is better than it was, but is still losing some water. I think it had a bigger crack in it than the other one, and putting a second patch over the crack may be successful.

As for the pond, well, it’s also better than it was. The join between the mortar and the pond liner is not at a constant level, and over to the left hand side of the pond, the water line is above the join. In other places it is below the join. I will have to observe the level of the pond over some days as it gets topped up with rain from time to time, and try to work out where it is leaking from. The liner and the mortar appear to be sound, so the most likely place is where there is a fold in the liner and it is harder to get a watertight join. In this particular example I have accidentally left a gap in the sealant, so this could be a place where the water is leaking out.

A fold in the pond liner

However, this setback is not going to stop progress, as the shallow pond is still usable and I am not going to empty it out again any time soon to try another repair. So I went over to the temporary pond and got ready to start battle.

The temporary pond

When you have a mass of vegetation like this, it is too heavy to pull out of the pond in one lump, so I had to break off bits, and I also had to saw through the water lily’s rhizome. I wanted to save some of the plants and put them in quarantine in the shallow pond. The reason for the quarantine is that the pond contains the highly invasive New Zealand Pygmy weed, which I have decided not to keep in my new ponds. I did, however, want to keep the Ponderia cordata, Iris laevigata ‘Midnight’ and the water lily Rose Magnolia. So I broke off sections of them, washed them well to remove all the pondweed that I could see, and planted them in new containers. The pond is too shallow for the water lily to be happy, but I am hoping that once it’s out of quarantine, I can put it in the raised pond, which it should like a lot better.

Plants in quarantine in the shallow pond

And then I tipped all the rest of the vegetation out of the temporary pond. I can now tip out the rest of the water and any creatures lurking in it, and start filling the hole in.

The wreckage left after removing the plants from the temporary pond

I hope that the displaced creatures will turn up in the shallow pond. The pondskaters have already moved in.

Today was a big day for the shallow pond. I cracked open my tube of Gold Label Pond and Aquarium Sealer, which had been sitting on my bookcase for six months, and squirted it all along the join between the mortar and the liner. I had calculated that the recommended 5mm bead width would leave me with plenty over, but I think I ended up applying it thicker in some places. It is quite tiring squeezing the trigger of the sealant tube gun, and my bead was not always smooth, but that doesn’t matter. I took the following picture standing on the back of the raised pond.

Shallow pond waterproofing overview

And here is a close up view of my waterproofing attempt.

The corner of the shallow pond in front of the pieris

I had enough left to repair the water butts. My last attempt, documented at Water butt repair lasted less than a year. So I removed the old silicone sealant (very easy) and stuck on some patches of pond liner with the rest of my Gold Label. They stuck very easily, and I also applied some sealant around the pipes connecting the water butts to each other and the drain pipe, and I managed to use the whole of the rest of the tube.

Water Butt Repair Attempt 2

Originally I had planned to use the leftover sealant to stick the rainbow cobbles to the liner, but I decided that I would rather find out first whether I had succeeded in getting the pond waterproof, and then buy some more sealant to stick the cobbles to the liner. The manufacturers recommend using their black sealant rather than the colourless for sticking stones to liner because it’s thicker and thus is better at holding the stones in place until the sealant is cured.

The sealant was easy to apply and came off my fingers with just water. Can I believe that such a benign substance can really keep my pond stuck together underwater? Well, we have some heavy rain forecast for Sunday and I hope that I will find out soon.

The repair to my patio (see last entry) seems to be satisfactory. I have tripped over two geraniums and a trowel so far, but have not tripped over my newly laid slab, despite not having re-grouted the area yet. So I will press on with laying my stepping stones and see what happens.

Eurgh, you’re so wet. You’re spoiling my grouting. Where did you get that liner? It looks like it’s seen better days. Can’t you lose a few pounds? I think my slabs are going to give way.

Yes, the pond is on the critical path.

All progress now depends on getting the shallow pond waterproof so that the contents of the temporary pond can be moved to the shallow pond and the temporary pond filled in. The other activity that matters is to get the stepping stones concreted in. The reason this is important is that I need to find out whether this is a job I am capable of doing myself or whether I need to get it done professionally, which I would want to do at the same time as the final landscaping work.

My mortar repair has now had two weeks to cure, so like a quack doctor I have declared it cured whether it is or not. I have applied two coats of V8 Pondseal and will put on one or two more later on today. Although I scraped away all the loose bits last week, the mortar is still quite crumby and I would not be surprised if I find that I have to repair it again within two years. I hope that next time I will be able to do a better job.

I decided to test my ability to lay slabs on mortar by replacing a loose slab in the patio. This is the hole that I chiselled out for the new mortar.

The place where the loose slab is supposed to go

I then made up 1 litre of 4:1 mortar, stuck it in the hole, and put the slab on top. I tried to get it as level as possible given that the slabs are naturally uneven and weren’t level themselves. It was quite easy to get it approximately right. The spirit level is obviously the best guide, but when the slabs are uneven, putting your head on the patio and looking sideways at it can help too. But I have now found what is really, really hard, and that is to just leave it alone when it is approximately good enough instead of making continual micro-adjustments. With any luck, when laying stepping stones, there won’t be so many adjustments to make because each slab is separate.

The slab replaced

I won’t know whether I have done a good job or not until I have replaced the grouting and then can find out if I keep tripping over the slab.

Encouraged by this possible success, I decided to start work on the diagonal path behind the apple trees. The reason for choosing this one first is that if I get it wrong it won’t be as noticeable as if I get the other path wrong. I ruthlessly pruned the buddleia, then took away the compost bag liners covering the soil under the diagonal path, set up some string and adjusted the spacing so the slabs are 22 cm apart. This is about the maximum that is comfortable for my stride length. I have made them parallel to the lawn edging. I want them to be the same level as the lawn edging, but the hard standing around the greenhouse is lower than the lawn edging and I need to have the first slab in the path at about the same level as the hard standing. So I think I will have that slab lower than the other three.

The diagonal path measured out

Each slab is 60cm square, and I calculate that if I use 2.5 cm of mortar to bed them on, I will need to mix 9 litres of mortar for each one. This is nearly twice as much as I made for the pond repair. This means that I probably have only enough endurance to lay two stepping stones in a session. It also means that I am going to have to go to B&Q and buy a lot more cement. But that is a problem for another day. The pond is on the critical path and must take precedence.

Now we have chalked up another wet weather record (the wettest summer for 100 years) the rain seems to be resting on its laurels and we have a fairly dry week coming up. Today I decided it was time to tackle the shallow pond. The problem is that the water leaks out of the pond at the join between the mortar (or render – I am not sure of the difference) and the liner, whereas I want the pond to be able to fill up right to the top. The mortar has been applied in a slope, which means that the join between the mortar and the liner is very thin, and it’s also quite ragged, so it would be difficult to apply a bead of pond sealant compound, which is what I want to do.

Original mortar, with ragged edge

So I chiselled off the thin edge of the mortar, roughened the rest of the mortar up with lots of scratches from the chisel, and then mixed up some new compound to make a vertical edge that would form a better junction with the pond liner.

Mixing mortar is not something I have ever attempted before, but I have iced plenty of cakes, and I read the books and did my best. I mixed it in an old washing up bowl, and I used 1 litre of cement to 4 litres of sand. At least one of my books said that sharp sand was better than building sand, but I think that was wrong in this case, because sharp sand has lots of big bits of grit in it, whereas I think it needed to be smooth. I then realised to my horror that I had probably made far too much. Unlike cake icing, you can’t just put the excess in the fridge and eat it later with a teaspoon.

I was careful not to make the beginner’s mistake of putting too much water in the mixture, but I may have made the slightly more advanced mistake of not putting enough water in it. I don’t know what happens if it hasn’t got enough water in it, but it may not be very good. I kept wetting the old mortar as I applied the new and it probably ended up wet enough in the end. And I was pleased to find that although I had made a little too much, there was not a lot left over. I made it into a little square patty and left it to bake on the tarpaulin so I can then use it for hardcore for laying my stepping stones. Then I washed everything out and poured the washings onto the tarpaulin, where the water can evaporate over the next week, and then I can sweep the dust up and dispose of it.

I can’t pretend that the end result is going to look pretty.

My new mortar patched onto the old

However, I just want the pond not to leak at the moment. If I achieve that, I will stick lots of cobbles around the edge of the pond and they will hide most of the mortar. My cunning plan is to glue the cobbles that are further away from the edge to the liner, but not the ones that are right up against the edge. Then the cobbles further down the liner will stop the top ones rolling down to the bottom, but I can remove them if I need to make any more repairs to the mortar or the watertight seal.

So the plan is now to wait a few days, and then check to see if there are any bits that need improving, and make a small amount of mortar to mend them with if necessary, and then wait a few weeks for the concrete to cure, and then paint it with Pondseal.

And then I iced a cake. Much easier.

Chocolate cake, iced using knife, not pointing trowel