Nothing is more disappointing than spending hours prepping and starting your seeds only to find out your seeds don’t germinate. What happened? Now what?
Every spring, we start seeds again, and things don’t always go perfectly as we hoped. I always notice that some seeds don’t germinate, leading me to wonder what happened and where I messed up.
What’s even more frustrating is when you feel like you’ve done it all right.
You gave them water, you kept them warm and tended to them daily. So, when you only receive silence from your seed trays, you get frustrated.
What could possibly be wrong? Should you get up?
The first thing you need to do is try again. Starting plants from seeds helps you save money and gives you diversity in your garden plants. Not to mention the immense feeling of pride you get when you see a lush garden full of plants you started from seeds.
Starting seeds is a skill that you need to practice and hone. Once you learn it, you can teach others how to start seeds at home.
The first thing you need to do is determine why you seeds aren’t germinating. Let’s look at several of the common problems.
13 Reasons Why Seeds Don’t Germinate
Most of the reasons that seeds don’t germinate is because of environmental problems. These lead to the most germination problems.
It’s important to remember that the three most important things seeds need are water, oxygen, and the proper temperature. If those things are messed up, germination will be as well.
1. Not Enough Water
Seeds cannot germinate without water. Mature seeds are dried out after the plant dies, and in order for germination to take place, mature seeds must be exposed to plenty of water. Once the seed absorbs enough water, the cellular metabolic process begins, and the seeds germinate and sprout.
All this basically means seeds NEED water.
Once your little seed absorbs water, the hydrolytic enzymes start the process of turning stored food (that’s inside the seed) into chemicals needed for germinating and sprouting. Many people have no idea that seeds actually have all the nutrients they need stored in the seed for them!
Some seeds have a hard coating on the outside that needs to break down before sprouting happens. This is one reason why soaking seeds is helpful!
One reason your seeds aren’t germinating is because you failed to give them enough water to lead to these important processes.
Check your seed starter trays or seed pots, and determine if the soil is too dry. If the soil is dry, add more water!
2. Too Much Water
So, you know that you need water, but sometimes, too much of a good thing is a bad thing. That’s what happens when you add too much water – seeds don’t germinate!
The amount of water you need to add depends on the seeds you want to sprout. Overwatering often leads to poor germination or patchy, inconsistent germination.
The problem is overwatering is that it causes the soil to become soggy and compacted, and then too much humidity leads to an extra problem I discuss down below – damping off.
If you watered too much, it’s possible that you may be able to save your seeds by allowing the growing medium to dry out. However, if overwatering caused other problems, you may have to start over completely.
3. Inconsistent Moisture
Seeds do best when they have consistent moisture. That doesn’t mean you need to drown them, but keep the soil at a consistent level of moisture.
Seeds don’t like going from super dry to soggy and then dry as a bone back to soggy.
4. Lack of Oxygen
Oxygen is necessary for germination and plant growth. It helps with the metabolism until photosynthesis takes over, so before a seedling truly develops, your seeds need oxygen to get its energy from aerobic respiration.
Oxygen is equally important as water for seeds and the breaking down of the exterior coating, but proper water is linked to the correct amount of oxygen.
Overwatering and under watering lead to a lack of sufficient oxygen amounts for your seeds. The biggest issue is overwatering because it leads to waterlogged and compacted oil that oxygen can’t move through.
Sometimes, planting depth matters too and affects access to oxygen!
5. Incorrect Planting Depth
Seeds need to be planted the proper depth to encourage germination. If they’re planted too deeply, the seeds won’t receive the light and oxygen needed to stimulate germination and sprouting. The sprouts need to be able to quickly reach the surface and start the process of photosynthesis.
Check the back of your seed packet. Most show you the recommended depth to plant each seed.
If there is no depth listed on the package, triple the seed’s diameter and use that as a planting depth.
6. Too Cold
Temperature matters as well; it plays a factor in cellular metabolism and growth rates. Seeds need to be in a specific temperature range to properly germinate, and if they’re too cold, they’ll stay in their dormancy.
Most garden seeds germinate in average room temperature between 60 to 75 degrees F, but that’s not true for all seeds. Some seeds germinate at temperatures just above freezing when the soil is col, and others want much warmer soil temps.
The problem of seeds being too cold is more likely to happen when you sow seeds directly outside than when you start them indoors. If you sow your seeds too early, the air or soil temps may be too low, or a sudden temp drop at night could stop germination in its tracks.
Starting seeds indoors is one way to avoid this problem before transplanting them into their final garden place. However, some seeds do best when started outside, so try protecting the seeds with a cold frame or a row cover. This keeps the soil at a consistent temperature needed for your seeds to germinate.
Related: $20 Simple DIY Mini Hoop House
If you’ve already placed your seeds outside, you may have to wait for them to germinate, but the cold could have killed them. Resowing the seeds may be your only option.
7. Too Hot
Another reason that seeds don’t germinate is that they’re too hot. This happens if you start seeds in the middle of the summer or start seeds in a greenhouse that is too warm.
Cool-season crops aren’t a fan of hot temperatures. I tried germinating spinach seeds outside in the summer, and most never sprouted. It was too hot for them. If you want to start fall garden seeds in the summer, make sure you start them indoors.
When starting seeds indoors, make sure they aren’t near a stove, oven, or a heat vent that could cause the seeds to be too hot. Greenhouses and polytunnels tend to get too hot, so open the doors and make sure they have adequate ventilation.
If you want to start seeds outside, they’ll need shade and mulched soil to reduce the temperature.
8. Not Enough Care Given
Seeds need to be given care and babied while they grow. All plant seeds vary when it comes to how much care they need, and their needs vary as well. You can’t apply what tomato seeds need to all seeds; that’s how they fail.
So, take care with your seeds. Learn what each one needs and do your best to provide them with the environment they need to thrive and grow.
9. Damping Off
Sometimes seedlings germinate, but they wilt and die quickly afterward. Leaving you wondering what happened.
This problem is called “damping off,” and it affects most seedlings. It’s most often seen when you sow seeds indoors early, and it caused by different soil-borne fungi and organisms like Pythium, Fusarium, and Rhizoctonia.
These fungus attack seedlings after germination, causing them to collapse and die. You may see white mold around the affected seedlings, but not always!
What can you do now?
This typically happens most often with homemade compost or growing mediums. It could mean that organisms found your compost. You may need to steam and sterilize the mix to destroy pathogens.
Make sure you clean trays and pots before using them, especially if you’ve had damping off problems before. Work on good seed starting hygiene and dispose of affected materials. Then, make sure you sow your seeds thinly to avoid overcrowding, and never overwater.
10. Low Germination Might Be Normal
Some seeds have a lower germination rate than others. Typically, you only get a 90% germination rate with the best seeds, but some species have a lower germination rate.
Check the seed packets before buying or research what you are trying to grow. Some seed companies will send more seeds if they realize their batch is germinating at a lower rate.
11. You Stored Seeds Incorrectly
Improper seed storage also is a reason that seeds don’t germinate. The seeds lose their viability over time if not stored correctly.
Storing seeds where the temperature is too high is a problem, and sometimes, this is out of your control if the garden center or transit was too hot.
Seeds cannot be stored in “too cold” of temperatures considering the freezer is the best place to store them.
12. The Seeds Are Too Old
Seeds don’t last forever; they have an “expiration” date. So, if you’ve had your seeds for several years, it may be that the seeds are simply too old to germinate.
Viability decreases over time.
How long your seeds have viability depends on many factors, and some seeds lose viability faster. For example, carrots and parsnips lose viability quicker.
13. Pests Ate The Seeds
Typically, this only applies to seeds planted outside or a greenhouse. Sometimes, pests or other little critters eat your seeds before they have a chance to germinate.
Birds, rats, voles, and mice are some culprits that love to eat seeds, but pests do as well! If you notice this is a frequent problem, start the seeds inside your home or try protecting your seeds with a row cover or cloches.
How to Find Out if Seeds Will Germinate
Some factors aren’t possible to determine ahead of time, but you can check to see if your seeds will germinate with a few at-home easy tests. These will give you an idea of the germination rate.
Water Test for Viability
Here’s an easy test.
Viable seeds sink in water, so dump seeds into a container of water and let them sit there for 15 minutes. Any seeds floating are likely not to germinate or will have a poor germination rate.
This test works great on larger seeds; it won’t work for tiny seeds because they tend to float due to their weight and size.
Putting seeds in water does trigger germination, so only do this when you are about to plant them anyway and want to determine how many will germinate.
Sprouting Test for Viability
Here’s another simple trick that you can use to test if seeds don’t germinate.
Start with 10 seeds from your packet and dampen a paper towel. Lay the seeds in a row, folding the paper towel over the line of seeds.
Put the folded towel into a Ziploc bag and close it, keeping it in a warm place out of direct sunlight.
Check daily for growth and make sure the towel stays moist. Within a week (or the expect average germination time for the seeds you are growing) passes, if no seeds germinate, the seeds are bad.
If some do sprout, use this ratio for the rest of your seeds. For example, if 7 seeds germinate, you have a 70% germination rate for the rest of the seeds.
If your seeds don’t germinate, don’t panic. Start over again and remember these reasons for seed failure. Avoid overwatering and keep your seeds at the proper temperature to increase the likelihood of a good germination rate.