Dutch Version
Hungry Plants

Making a Bog Garden for Carnivorous Plants in the garden

Quite a few hardy carnivorous plants can be grown outside, even in the Netherlands! But you cannot just plant them in with your flowers or vegetables. The soil and water is wrong and there is too much food (nitrogen) in the soil. You need to make a bog or swamp for them. The site must be in full sun, although you can get away with having some shade at times. CPs grow in bogs where they are open to full sun with perhaps the odd pine tree providing shade. It can be any size, but a larger one will hold more water in it during dry periods.

Bog Garden What do you want to grow in the bog? You can grow Sarracenia (Sarracenia purpurea ssp. purpurea is the hardiest varity as it grows in Canada), Darlingtonia, Venus flytraps, hardy sundews and butterworts that form a resting bud. Sarracenia will form a clump in few years and can self seed itself if insect pollinated. Drosera will self seed easily the first year, and plants like D. filiformis, D. binata and VFTs will also form clumps over time. So take time to work out what plants you would like to grow then add space for the growth and self seeding of plants. Our native Sundews, D. intermedia and D. rotundifolia, and also D. filiformis and D. anglica,  prefer drier parts of the bog, and grow at different levels away from pools that form in a bogs.

Try and place the bog away from trees that lose their leaves over winter, as these dead leaves can lead to the loss of your plants due to mould and fungi which CPs are particularly susceptible to over the winter. The rotting leaves will also kill the winter buds of Pinguicula and Drosera and as the foliage rots, nutrients will be added to the soil, enriching it possibly to the detriment of your CPs.

A hose spray or water mister is handy when it has not rained for some time in order to keep the moss and smaller CPs from suffering from the effects of low humidity.  This can be avoided by using bog grasses like in nature, although put the taller grasses at the back to avoid hiding the smaller CPs. You may get heathers and mosses growing from the peat, so from time to time you will need to cut this back away from your CPs.

You can make the bog just like you would a pond, but fill it with peat instead of just water. If you already have a pond you can make a bog in it at one edge or along side it. A ready-made moulded plastic or fiberglass pond, or a flexible pond liner can be used to make the hole waterproof. When you dig the hole for the bog make sure you dig to a sufficient depth to hold an adequate amount of water, otherwise the sun will dry up your bog too quickly. If you use a pond liner, line the hole first with and old carpet, cardboard or even sand to stop any sharp stones making a hole in the liner. The water and soil in the bog will be heavy and any sharp objects under the liner will pierce it.

You can also build a wooden rail around the bog to bring the level of the liner about 3 inches (7 cm) above the level of the garden soil. This is for two reasons: one is to stop the muddy rain water washing into the bog, and the other is to put a layer of bark chippings around the bog which prevents snails and slugs from getting at your nice CPs. This is not 100% effective, but it certainly helps. It can also stop the grass cuttings from going onto your bog! If you use a plastic pond or container, leaving it on the ground (not digging a hole) will do the same thing.

Winter bog garden Once the hole is lined, fill it first with about 6 inches (15 cm) of perlite followed by 2 inches (5 cm) of Sphagnum moss peat which acts like a wick and pulls the water up from the reservoir (perlite) base.
The rest is a mix of Sphagnum moss peat, perlite and silver sand - a common mix ratio is 3:1:1. You could use peat and perlite, or peat and sand in equal amounts instead. To hide the perlite and stop it being washed away, finish the bog off with a layer of peat and sand or sphagnum moss. Make small hills and dips in the peat to give wetter and drier areas into which you can plant suitable CPs. One important point is when you make the bog you give a run-off area on one side for the rain as not all your plants will appreciate being under water over winter and especially rainy times. Wet all the peat with rainwater as you go and finish off with plants and sphagnun moss (which helps keep it humid).

Remember you do not need to have a big garden to have CP bog as you can also do something similar with big pot or patio planter on your patio. Just ensure that it is water tight and use the same soil mix as above. You can drill holes into the side of the container just below the soil surface to ensure it does not become flooded in winter and the plants rot away. Even in the wilds a bog has an area that acts like an over flow in wetter times, so plants are not underwater for too long. Smaller pots are more mobile and if you live somewhere with particularly cold winters then you can then just move these pots into a greenhouse or a sheltered area for protection. This type of bog planting can also be done inside the greenhouse for the more tender CPs, to show them off in a natural looking bog setting.

No plants are collected from the wild. All propagation is done artificially from division, rhizome cuttings or seed from artificially grown plants.
Site by Keith Wilson