I have geraniums growing from seed under lights. My first time ever.
They are 2-3 inches tall with some having 3-4 leaves. What do I do next please!
Hello – It sounds like you’ve already done the hard part of growing geraniums (Pelargonium sp.) from seed as your seedlings have germinated and are already 2-3 inches high.
If you haven’t already done so, your seedlings can now be transplanted into 4” pots using a soilless potting mix. When transplanting, be sure to grasp the seedling by a leaf rather than the stem to avoid crushing the stem.
Have you been fertilizing your seedlings? I’m including a link below to our Toronto Master Gardeners guide ‘Growing from Seed’. The guide suggests that once your seedlings are in their individual pots and have their second set of true leaves, fertilizing at full strength using a liquid fertilizer can begin every other week. Be sure to read the instructions carefully on the product you are using.
Following good cultural practices for your seedlings such as providing good air circulation and controlling soil moisture will help to avoid any of the issues noted in the ‘Special Problems’ section of the guide.
Before planting the seedlings in your garden, the seedlings should be ‘hardened off’ over the course of a week to gradually acclimatize them to the harsher outdoor conditions of fluctuating temperatures and exposure to sun and wind. Start by putting your plants out for just a few hours in a protected position and gradually expose the plants to more open areas and for longer periods as the week progresses.
Geraniums can be planted out once all danger of frost has passed. This can be a challenge to figure out as published last frost dates are average dates. One of the resources I checked suggested geraniums could be planted out once night time temperatures are consistently above 10°C. By keeping an eye on the 14 day forecast published by one of the weather services (I use the Weather Network) you can tell when this is likely to occur and then work backwards to determine when to start hardening off.
I hope you have enjoyed growing your geraniums from seed and are rewarded this summer with many blooms.
Toronto Master Gardeners: Growing from Seed