Begonia Seed Sowing Guide

Now that you've got your begonia seeds, what to do with these dust-sized specs?

Photo: roughly 30 begonia seeds on a sheet of paper next to a metric ruler

 

1. Begonia Seed Inspection

Whether you've just received seeds in the mail or opened your first seed pod, the first thing you will want to do is check their overall condition. You will need 2 pieces of regular printer paper. It is recommended to do this indoors, turning off any fans and reducing any air current which could cause the tiny seeds to scatter. Carefully open the seed packet (or ripe seed pod) over the middle of a sheet of paper. Healthy begonia seeds should roll easily when the paper is tilted.

video: the contents of an entire pod of begonia seeds is rolled on a piece of paper

 

Healthy begonia seeds are also brown-to-golden in colour and barrel shaped, although it is normally quite difficult to discern this with the naked eye. A jeweller's loupe can be an invaluable tool, and is easy to find online for under $20. We recommend any magnification above 20x, and perhaps most importantly, the loupe should have an integrated light. 

Slowly roll the desired quantity of seeds from one sheet to the next, and return the remaining seeds to the original paper. Store in a cool, dry place to prolong viability. 

2. Begonia Seed Sowing Container

The best containers for sowing begonia seeds are small, shallow, and air-tight. If it is microwaveable, you can sterilize your substrate at the same time. Tupperware is a good choice. Clean it well with soap and hot water before use to reduce the chance of spore contamination. 

photo: a suitable container for germinating begonia seeds 

 

3. Begonia Seed Sowing Media

You have a few choices when it comes to media for sowing begonia seeds! We will go through the pluses and minuses of a few common substrates here.

Organic/soil: Soil is the classic, easy-to-find medium that readily provides nutrition to freshly sprouted seedlings. However due to its nutritious nature, soil also promotes the most common problem for young begonia seedlings - damping off. If you want to use organic media such as peat or choir, it is highly recommended to sterilize it in the microwave before use to kill any algae or mould spores. 

photo: begonia seeds germinating on soil

 

Akadama: If you are feeling more adventurous or have had problems sowing on soil in the past, you may want to consider an inorganic media such as akadama. The advantage to akadama is that due to its porous nature, more air is provided to the roots of seedlings and damping off is far less likely. The disadvantage to akadama is it contains very little nutrition for seedlings, so early transplantation, or using a liquid fertilizer once seedlings have sprouted, is advised. 

photo: begonia seeds germinating on akadama

 

Aquarium Stratum: Stratum aka "aqua soil" is slightly more prone to algae than akadama, but still provides plenty of aeration to roots and contains more nutrients to help seedlings get their start. 

 

photo: begonia seeds germinating on Fluval Stratum

 

4. Water for Begonia Seed Germination

The very best water for your begonias happens to also be the most ecological. Rain water is extremely pure, but not stripped of all nutrients as is the case with distilled water. If you don't have any way to capture rain or snow, distilled water is the next best option. Reverse osmosis water is also fairly reliable, followed by filtered tap water. 

 

 5. Sowing Begonia Seeds

Pre-moisten and sterilize your substrate and container. Form a slide with the paper sheet, and tap to roll the seeds onto the surface of the media. Try to space them out evenly so the seedlings won't be bunched together when it comes time to transplant them. Begonia seeds are unusual in that they require light exposure to germinate, so it is very important that they not be covered or buried! Close the lid of your container and do not open unless the substrate needs to be watered.

 

6. Heat and Light for Begonia Seed Germination

Place your container in a warm (22 degrees Celsius and up) and bright location, that gets at least 12 hours of diffused light per day. Only open your seed container if it needs to be watered, and avoid watering directly over the seeds or seedlings. Begonia seeds can take between 2 weeks to 3 months to germinate, with the majority taking around 6 weeks. Happy growing!