The pots are filled and the seeds are lightly buried and gently packed in the perfect growing medium.
Now comes the stressful part: am I giving my young plants too much water or too little? How do I know the perfect amount of moisture to achieve growing success?
If you ask these questions, you are not alone. I spent many years watching my seedlings start beautifully before suddenly wilting to death or succumbing to mould and rot until I learned how to give the plants just the right amount of water.
Most newly planted seeds and young seedlings need watering about every second day. Of course, there are a lot of factors that affect how often you need to water including temperature, pot size, or growing medium.
Every growing season is different, and whether you start your seeds indoors or plant them directly in the garden, let’s learn how to tell exactly when a seed and seedling needs water, plus tips for successfully watering seedlings.
Related: 10 Common Seed Starting Mistakes to Avoid
Factors That Determine How Often You Need to Water Your Seedlings
Seeds and seedlings will generally need water every 1 to 2 days if they are grown indoors or in the garden. Seeds and young plants grow best with a consistent and even supply of moisture where the soil is neither soggy nor dry.
Of course, “how often” is determined by several factors including temperature, soil type, tray size, and heat from grow lights or heat mat, so in a hot dry year you may need to water every day or even twice a day. Make sure to check the soil every day in case watering is required.
Water your seeds and seedlings when:
You have a lot more leniency with watering seeds and seedlings in the garden as opposed to those grown indoors and in pots.
The soil in pots will dry out a lot faster than garden soil, and the moisture is limited whereas outdoor plants have the benefits of water deep in the soil and early morning dew.
As seedlings get older, their water requirements become less exacting. After a week or so after germination, you can probably cut your watering down to every second day. As they get even older, they benefit from a less frequent and deeper watering once or twice a week.
What Happens if You Overwater Your Seeds?
The obvious problem with underwatering seedlings is that they will dry out. In extreme cases, they will wilt and die.
Mature plants can rebound after drying out and withering slightly but young plants are often too delicate and are not resilient enough to sustain themselves without water even for a short period.
Another problem with letting seedlings dry occurs if your growing medium has peat moss. Dry peat moss becomes almost impervious to water and will shed any water you pour on.
What To Do If Plants Are Dry
If plants have dried out, get water on them as soon as possible and hopefully you caught them in time. If the growing medium containing peat moss is overly dry, soak it in a tray (see Bottom Watering below) until it has become sufficiently rehydrated.
What Happens When Seeds And Seedlings Are Overwatered?
You might think that wilting seedlings is the worse problem you can face so you add lots of water, but this is not often the best solution. In most instances, it is better to underwater than overwater. Overwatering seeds and seedlings can lead to issues such as:
How To Help Overwatered Seedlings
For seedlings in trays, move your plants into a sunny, dry, and airy place to facilitate drying.
If you are growing in the garden, don’t water your garden until it has sufficiently dried out (and hope it doesn’t rain).
The Proper Way to Water Your Seeds And Seedlings
Sometimes, we will have the greatest success with a plant if we start it in a container. Many vegetables, such as tomatoes, cucumbers, and peppers are excellent for transplanting and lots of flowers benefit from starting early indoors as well.
There are 2 ways to water seedlings: bottom watering, and top watering.
Bottom watering uses the principle of capillary action, where water is drawn from areas of high water concentration to areas that are dry (or have a lower concentration of water).
Place your tray or pot inside another tray or shallow bowl. Fill the bottom tray with water and let your seedlings sit in it for an hour or two.
After this time, check the soil moisture. If it is still dry let it sit longer. Once the soil is moist enough, dump out any remaining water.
Bottom watering is by far the most gentle way you can water your seedlings and has the advantage the soil takes on the right amount of moisture that it needs.
Top watering plants means pouring the water onto the soil from above.
Watering indoor plants is a whole different ball game than watering the garden. In particular, the growing medium of indoor plants is light and will be easily disturbed by watering which will wash seeds away or break the stems of seedlings.
Here are the best ways to top water potted seedlings:
Many indoor seeds and seedlings will do well with a light mist from a spray bottle. This might have to be done every day (or even twice each day) since it only waters the surface and does not sink into the soil.
Once the seeds have germinated and started leafing out, they may require heavier watering.
If you want a heavier watering than a spray bottle, use a watering can with a very fine head (or rose). You can also make one yourself by punching a few small holes in the lid of a pop bottle.
Water Gently With A Watering Can
No matter how you water, always water gently! If you are using a watering can, make sure it has a small rose or thin neck to avoid damaging the plants.
Look for a small indoor watering can as opposed to the large, plastic bulky ones intended for outdoor use.
Secrets To Watering Your Seedlings The Right Way
Here are some tips that will really improve how you water your seedlings.
Can I Water During A Drought?
There is nothing worse than watching your plants die during a hot dry spell, especially when there is a ban on water use.
Whether or not you can water your precious plants during a drought depends on your municipality. Always check with your local government on what restrictions are in your area. No matter how much you want to, never water if such action is prohibited.
If some watering is permitted, indoor and potted plants will often require less water than a garden because you only have to water the soil on the pots and not unproductive soil.
You can also control the environment of indoor plants to conserve moisture by adjusting the ambient temperature or moving them to a different location where they won’t dry out so fast.
How To Water Seedlings In The Garden
If you are like me, you prefer starting your seeds directly in the garden. It is delightful watching them spring forth and turn into a delicious jungle of greenery.
When your seedlings are young, they will do best with regular watering every second day or so.
As the soil dries out and we reach for our sprinklers, remember this isn’t the best way to water a garden.
A sprinkler is actually the least desirable to water the garden because a lot of the water is lost to the atmosphere or ends on the foliage where it evaporates or burns the leaves.
Here are some good ways to water seeds and young plants in the garden:
A soaker hose looks like a regular garden hose but it is permeated to allow water to slowly leak out.
Lay it out along soil near the stems of your plants and all the water goes directly to the roots. They are also very economical for large gardens.
While this is more labour intensive, you can get a can with a long neck that allows you to reach under the foliage and put the water directly into the soil.
Make sure the watering can has a small head (rose) that will provide a light sprinkle so as not to damage or deluge the young plants.
A simple garden nozzle is certainly the cheapest and simplest way to water but this isn’t the best way to water for reasons similar to a sprinkler.
If you use a nozzle, make sure to water with a light spray or fine mist otherwise an intense blast can crush tender seedlings or disturb ungerminated seeds.
Isn’t Rain Enough?
The best advantage of growing seeds in the garden is you can take advantage of all rain. However, rain isn’t always enough.
For many years we do not have to water our garden, but there are several seasons that are far too dry for the plants to grow. Is rain enough?
There is no answer for this as it depends on where you live, your climate, rainfall, drought conditions, and so much more.
Watering your plants can sometimes be a scary moment. Did I overwater them? Maybe I didn’t give them enough?
Or the ultimate when you remember on your drive to work in the morning that you forgot about them completely. Hopefully, this guide has given you some ideas on how to give your seedlings just the right amount of water.