Sunday, August 16, 2015

(Bad panorama shots of) the big spring clean!

Normally, I trim back the Sarracenia in Autumn, because the books tell you to remove dead growth during winter to eliminate disease risk. This year I didn’t. Why? Because some friends in the AUSCPS told me that they left foliage on their plants during winter and removed it as the first flower buds push through the rhizomes in Spring. The idea is that the dead foliage acts as a blanket to protect the rhizomes and the growing points. It also means the plants still have loads of green foliage to photosynthesis. These arguments sounded logical, and the people in question have beautiful plants, so I tried it.


So here is a (bad) panorama of the before…


And an even worse pano of the after! What a difference the removal of dead foliage makes! Now I can start watering to make sure all that Sphagnum is looked after. It has grown very well, given I planted a few handfuls last year. With luck, it will grow into an all-covering lush green carpet this year.

Saturday, August 8, 2015

DIY: make a vertical garden for VFTs

Vertical gardens are fast becoming all the rage, especially as new houses have less and less space for gardening. There are numerous designs to be found by searching on Google images, with new ones appearing regularly. Even though we are lucky to have a good sized garden, only a small area of it is really suitable for CPs, and it is pretty much filled by the four bog gardens. One thing about bog gardens is that the smaller plants in them, like VFTs, can easily be swallowed up by large plants like Sarracenia. So, to show off these plants better, I decided to try making my own vertical garden from some scrap pipe I had lying around (as well as to see if vertical gardens work for CPs).

Note: this is experimental for CPs. I have never used one of these gardens before for them. Try at your own risk, as it is untested! For those more patient, I will report back whether it works or not.

Also: your safety is your responsibility.

To make a pipe vertical garden, you will need:


  • 1 meter (3 foot) lengths of 100mm (4”; for VFTs or sundews) or 150mm (7”; for Sarracenia) PVC pipe
  • PVC primer
  • PVC glue (for non-pressure pipe)
  • Two end caps for each length of pipe
  • Two downpipe C-clamps for each length of pipe (choose an attachment type for your particular situation; mine are good for a horizontal runner, but other types are available for vertical surfaces)
  • 60 mm treated pine screws (you will need other fasteners if you are attaching to brickwork)
  • Washers of appropriate size for the screws
  • Garden twine
  • A gardening pen (or at least a pen that makes a permanent mark on plastic)
  • High speed electric drill + extension cord
  • A 76 mm (3”) or 125 mm (4.8”)  hole saw
  • Drill bits
  • Safety glasses
  • Tape measure or ruler
  • Acrylic or spray paint of a light colour (or not).

To start, you will need to figure out how to space out the centre of each hole. For a 1 metre pipe and 76 mm holes, the below spacing worked for me (assuming you loose 30 mm to each end cap):


The design I am making is specifically for VFTs but would also work for Drosera. If you want to try Sarracenia in a pipe garden, I would use 125 mm holes (5”) and 150 mm pipe (the depth will hold a lot more water). Approximate hole spacings for such a garden are given below, including separate holes for smaller Sarracenia species only, and overlapping holes for larger plants. For the overlapping hole design, you could use some wet and dry sandpaper or a file to round down the v-shaped intrusions and make a nicer hole (or the hole saw if you are really, really careful).

In case these layouts don’t work for you, I used Powerpoint to lay everything out and figure out the spacings. But note also that, no matter how careful you are, the holes will never be perfectly spaced, but close enough is good enough in this instance…

150 mm spacings

Now comes the tricky part: lining the centres up perfectly straight. To do this, I used garden twine to make a straight line. Do this by threading a length of twine two and a bit times the length of your pipe through the pipe, and tying a knot so it sits tight against the end of the pipe. This will create your straight line. Adjust if the string is not tight enough to make it perfectly straight, and then go ahead and mark out your hole centers with the pen and ruler, like this:

Pipe marking

Now comes the fun part: the drilling. Do this outside, as it will produce lots and lots of plastic shavings and burrs that are messy to clean up. Also, before you fit on the hole cutting bit, it pays to pre-drill each hole, first using a small bit to make precisely laid-out holes, and then a bit the same size as the one on your hole saw. If you don’t, the hole saw will bounce off the pipe as its drill bit punches through. The result will be a rough hole, blood (or worse!), or all of the above.

Don’t risk it! Also use safety glasses, as plastic will fly everywhere from the hole saw.

When using with the hole saw, apply gentle pressure to avoid unevenly cut or rough holes. When you are done, your pipe should look something like this:


I used wet and dry sandpaper to remove the burrs from each hole.

Next, glue on your end caps. Again, this needs to be done outside, as both the primer and glue are dangerous solvents that will harm you!  Start by cleaning about 40 mm of each pipe end with a rag doused in PVC primer, as well as the inside of each of the end caps. Next, working quickly but safely, paint the inside lip of an end cap and 30 mm or so of the outside of one pipe end with the PVC glue. Then fit the painted end cap firmly over the painted pipe end and hold together tightly for at least 30 seconds to let the glue start to cure. Repeat for the other end, and then let the pipe rest for 5 minutes or as per glue directions to allow the glue to cure. My glue needed 24 hours to dry completely.

Once the PVC glue has completely dried, you can paint the pipe, if you choose, to make it look cheery. I am thinking of using either yellow or light green paint make it stand out but compliment the natural colours of the VFTs. White will reflect heat if you are in a hot area. Never use black or dark colours, as it will likely turn the garden into an oven. Acrylic paints will also last a lot longer and protect your pipe, but are not as easy to apply as spray paint.


After my glue had dried, I used the C-clamps to attach the pipe to a fence. Make sure you fit washers to each screw used to ensure a good fix to your surface. Also, line up the C clamps so they fit over the a space between two adjacent pipe holes before you drill, as shown. And before you tighten the clamps all the way up, make sure the holes are level so water will not overflow out of one side. I used spare washers to make sure the pipe was level, which will in turn ensure a level water table. I will hook this pipe garden up to the irrigation system for the rest of the garden using two tricklers. I will also fill the pipe with water once cured and figure out where to drill drainage holes so the peat will not be waterlogged (I will be aiming to place the drain small holes at about 75% the depth of the actual water level in the pipe).

Next up: filling with CP mix and planting out.

Wednesday, August 5, 2015

All about Flickweed

Flickweed is common in CP collections, but talking with close friend Jessica about it a few months back, I realised that I really new very little about it. A chance encounter with it the other day gave me an opportunity to read up about it, so here is a summary of what I learned:


Flickweed (Cerastrum hirsuta) is a small herb that is a native of damp areas in western Europe and North Africa. It is also known by many other names, including hairy bittercress, snapweed, shotweed and pepperweed. From a CP perspective, it is an issue because it spreads like wildfire in both bog gardens and potted CP collections.

Cardamine_hirsuta_flower Cardamine_hirsuta_flower_close

Above are some close-ups of the flowers, which are like very tiny, dainty goblets.


Flickweed gets its common name because it produces specialised, elongate seed capsules called a siliques, which are shown above. When the seeds are ripe, the sides of the silique split open if they are touched, explosively launching the seeds over distances of nearly two meters. At right is a close-up of several siliques.

The explosive method of seed dispersal means flickweed can soon establish itself throughout a CP collection. This happened with the first bog garden I had in Queensland. It got in because a few plants were growing nearby the bog. Once it was in, it needed a complete removal of plants and fresh peat to eliminate it. Subsequent bog gardens were all raised, and I think this may have helped by keeping the soil away from plants growing in the garden.

I don’t have flickweed in my collection because I have been very careful to make sure I removed any plants before they made it into the collection, and then kept a constant eye open for seedlings and removed them before they produced flowers. I had hoped that it would be a scourge I would not have to manage due to our cold winters. However, I have started to notice flickweed appearing as a weed of garden beds around Canberra. These pics were taken at CSIRO Black Mountain.

Cardamine_hirsuta_wp_JN  Cardamine_hirsuta_wp_JN2

Once established, flickweed clumps up fast and can also form dense carpets. Attempts to weed it result in more seeds being dispersed. Sadly, it will require a complete and simultaneous removal of media (including from roots of plants) to eliminate it when established in a bog garden, followed by a vigilant watch for stragglers afterwards. It can be easier to eliminate from a potted collection, but be sure to check around the edges of pots and also drainage holes to make sure you get every plant, and keep checking for and remove re-growth as it occurs. Prevention is the best cure, so it pays to remove any flickweed present from new purchases and keep the new plants quarantined to eliminate the possibility of seedlings. Weeding is really only practical to eliminate populations that are just starting out, but be careful not to spread it further if it is in seed. Herbicides do work, but they are impractical in collections.

As for my collection, its still freezing cold here, and I’ve been taking plenty of pics of frosted up plants. They will feature in a separate post sometime over the weekend, along with a bizarre “weed” that came up in Sphagnum moss that I don’t have the heart to kill off. Spring can’t come fast enough!