Sowing sundews from seed is one of the easiest ways to build a collection of Drosera, they are easy to grow as both seedlings and plants. They usually germinate quickly and have high success rates making them the perfect for beginners to grow from the seed for the first time.
Sub-tropical Drosera, which includes the common Drosera capensis, aliciae and spatulata, is the easiest group of sundews to grow from seed and care for which can be grown happily either inside or outside. There are multiple easy to grow sub-tropical species available allowing a grower to grow multiple different sundews at a time. Most of these sundews have self-fertile flowers which means they do not require pollination. Some of these species are able to produce thousands of seeds from just one flower stalk. In general most sundew seeds are very tiny, like specs of dust and thus easy to sow hundreds unintentionally at a time.
(From left to right) Drosera capensis seed next to a 5p coin, Drosera flowers and Drosera dried flower stalks ready to harvest.
Temperate Drosera, which includes Drosera intermedia, anglica and rotundifolia, is also an easy sundew to grow from seed providing cold stratification is provided. These cold temperate sundews which often produce a hibernacula (dormant resting bud in winter) are perfect candidates for outside or in a unheated greenhouse setting.
(From left to right) Drosera filiformis hibernaculum, D. anglica seedling and D. rotundifolia with flower stalks
Tuberous, petiolaris complex Drosera and other species of sundew are slower and sometimes more difficult to grow from seed and may require special conditions to germinate successfully dependent on what species you are growing. Others are less reliable at producing seed from flowers such as pygmy sundews which are most easily propagated from gemmae. Therefore for other, more difficult and uncommon species of Drosera seed it is important to research the required methods and conditions before attempting to sow from seed and not recommended for first time seed growers.
The following guide is the method I use for sowing most sub-tropical sundew seeds as well as temperate sundew seeds. This is a quick, simple method and not a lot of hassle if you are new to growing carnivorous plants from seed.
How to Sow the Seeds:
Firstly, select the pot you are going to use to sow the seeds. I like to use either a 7cm or 9cm square pot dependent on how many seeds I am going to sow. You can use any size pot you wish or even use seed trays or cell trays, depending on how many seeds you have to sow.
Next select the media you wish to use. Personally I like to use finely chopped sphagnum moss or peat and sand in order to sow my Drosera seeds. I like to use a fine media to sow my seeds onto as they are so tiny they can easily fall into large pores in the media or long fibered sphagnum so I will usually chop my sphagnum up to use a fine layer of it on the top. You may also use straight peat or peat and perlite/grit.
Fill the pot with your chosen media and then using a watering can with a rose to water from above so that the media is fully saturated before sowing.
Once the media is fully saturated, sow a small pinch of the seeds as evenly as possible on the surface of the media (If you have temperate Drosera seeds they will need to be stratified before sowing, see how to do this below).
You can either use your fingers to sow the seeds or use a piece of paper with the seeds on to gently tap onto the media which I often find easier to use as the seeds gently roll off and you can see them more easily. Do NOT bury the seeds.
Write out a label with the name of the Drosera species and date if you wish and then stick it in the pot to ensure you can distinguish different species if you have multiple seeds to sow.
Place the pot of seeds in a saucer or tray of rain, distilled or reverse osmosis water. Do not let the pot dry out at anytime. Place the pot on a bright window sill or under a grow light, you do not need to provide full sun until the seeds have germinated so a bright spot will suit just fine. You may also wish to use a plastic bag or place seeds inside a propagator. Personally I have never found this necessary and the seeds will germinate just as well without the additional humidity provided by the bag.
The seeds will usually take 4-8 weeks to germinate depending on the conditions. Cold temperate species of Drosera will often take longer depending on when they have been stratified and whether you are naturally stratifying them outside which in that case means they will germinate when the weather warms up in spring.
When the seedlings are a couple of cm tall you can move to a bright and sunny spot such as a south facing window and treat as adult plants. See my blog on growing sub-tropical sundews here
Various Drosera I have grown from seed both germinating and at tiny seedling stage, all taken under a macro lens. Images include seedlings from Drosera venusta, D. collinsiae and D.regia
Stratifying Temperate Drosera Seed:
Temperate Drosera need a cold period in order to break the seed dormancy to germinate, the seeds need at least one month of cold in order to germinate successfully. There are two ways to stratify your sundew seeds.
Firstly is the fridge stratification method, this method is more time consuming and can be fiddly but is best for people who cannot provide the cold period that the seeds need naturally. The easiest way to do this is to finely chop up a little bit of damp sphagnum moss and place in a small ziplock bag, then place the seeds on top of the moss in the bag. Leave the bag in the fridge for 4 weeks. After this time take the seeds out the fridge and then spread the moss with the seeds on top of your prepared media.
Secondly is letting the seed stratify naturally outside in an unheated greenhouse or similar. Simply sow the seeds in the method stated above anytime between November and February and then place the pot in a cold spot as if you would plants during dormancy. The seeds will germinate when the weather warms up in spring.
Best seeds to start with, for beginners and first time carnivorous plant seed sowers:
Sub-tropical sundews:
Drosera capensis
Drosera aliciae
Drosera spatulata
In order: Drosera capensis 'alba', D. aliciae and D. spatulata
These three species of sundew are perfect for beginners as both seeds and plants. From seeds these are the fastest growers and in the correct conditions will produce a almost fully mature plant in the first year!
(Left) Pot of Sarracenia capensis from seed at the beginning of the year. (Right) The same pot of Drosera capensis at the end of the year.
Temperate sundews:
Drosera rotundifolia
Drosera anglica
Drosera intermedia
Drosera filiformis
In order: Drosera rotundifolia, D. anglica, D. intermedia 'alba' and D. filiformis