How often should I water my herb seeds and seedlings?
All seeds require water to germinate, and all seedlings require water to survive. Everyone knows that, and with that in mind, one of the most common mistakes of an enthusiastic grower is to over-water everything!
The key to watering your seeds and your seedlings is to find the sweet spot to ensure they don’t dry out and they don’t become waterlogged (the plants’ roots and the microorganisms in the soil all need air as well as water). The amount of water needed will vary according to the temperature and the type of compost you’re using. It’s easy to tell when the soil is starting to dry out – just keep a close eye on them and make sure you have a system in place to provide water when it is needed, especially when the weather starts to warm up.
There are two main schools of thought with watering; the first is watering from above, the second is watering from below. We usually water our seed trays and young seedlings from above using a system that produces a fine mist. You can replicate this by using a spray bottle with a misting nozzle or a ‘pump action sprayer’. Try to avoid watering seeds and young seedlings with a watering can or hose (unless it has a misting nozzle on the end), as too much force will knock over delicate seedlings.
The second option – watering from below – relies on capillary action for the water to be absorbed through the soil from the bottom to the top. To do this you’ll need to keep your perforated trays or pots in a non-perforated tray that can be filled up a few inches with water. This can only really be done indoors, or under shelter, where it won’t fill up with rain. The main advantage of this method is that it prevents any soil disturbance while you are watering.
In addition to watering you also need to consider humidity levels. This is especially relevant if you are growing on a window sill inside where humidity levels are low. One way around this is buy a small propagator with a clear cover, or you can cover your pots in cling film between watering.
Whichever watering method you go for, it’s always good to pre-moisten the soil (if it isn’t already) before sowing your seeds, and remember it should be moist, not waterlogged.