When Should I Give Up on Seeds That Have Not Germinated?

Hi everyone,

I'm new to this forum (and gardening in general), and as I am based in South Africa where spring is about to begin, I wanted to pick the brains of those of you about to finish spring and summer.

I planted some seeds last week. After much Internet research, I started them in damp potting soil (we don't get seed starting mix here), covered them with plastic and put them in a nice warm spot. Much to my excitement, five days later my marigolds and gazanias started showing signs of life, and now, ten days later, I'm looking at a 75% germination rate for the marigolds and about 50% for the gazanias. I uncovered the pots as soon as the first shoots came through, and have them outside in the sun for 12 hours a day. Since the initial 3-4 seedlings, the marigolds have consistently been germinating, with a new seedling just about every day. The gazanias, however, have not put out new seedlings for about two days now. What with the pots being outside, the surface is drying out quite quickly, so I'm making sure that I mist frequently so that the seeds do not dry out.

Which brings me to my question (and before anyone else says it, I know you have to have lots of patience to garden). Is it normal to have some seedlings come up quickly, and others, from the same packet and living under the same circumstances, only come up days or weeks later? At which stage do I consider any seeds that have not germinated as lost? I'm not going to do anything until I need to move the healthy seedlings to bigger pots, but if the other seeds have not germinated by then am I safe to assume they are never going to? Is there anything I can do to help them along?

I think if they haven't germinated by the time you're ready to pot up the other seedlings then they're probably not going to. It is normal to have some variability in when they germinate, but for things like this that germinate within 10 days, you may see more germination over the next several days or even a week or two, but after that chances are lower that any more will come up (unless your seeds were different ages or from different packets, often older seeds will be a little slower to germinate) Assuming you planted all the seeds to the same depth in the same soil and are keeping them equally moist and in the same amount of light, there's really not much you can do besides sit back and wait--it's rare to get 100% germination on anything, some of the seeds in the packet are no good in the first place and then a few probably got planted slightly too deep or were slightly too wet or too dry, etc.

Cheer up, some tree seeds take two years to germinate! Quite a lot of seeds take three or four weeks. Some seeds need special treatment, such as chilling for a period. Learning about them is all part of the fun of gardening.

If they haven't germinated by the time the earliest seedlings have two sets of true leaves, then they might not germinate at all, but the only way to tell would be if they rotted. If they haven't rotted, they're still alive. Usually I have found that domesticated plants, especially named varieties, and even more so named varieties of annuals, germinate quickly and more or less all at once. Wild seeds or as someone else mentioned, tree seeds, can have very staggered germination, because that's a help in the wild where conditions might be changeable. The other thing is that it is normal for only X% of any seed to germinate.

For myself, it depends on how many seedlings I get and how much I want more plants. I will keep working on a group of unsprouted seeds if I'm desperate or determined enough.:)

As far as fast germinating seeds I would give up fairly fast. If half the seeds came up in 10 days and you're at 20 days the rest of the seeds are probably not going to grow. In that case I have a small bed where I just toss the dirt and seeds, maybe they will come up but t's up to nature at that point.

Something like marigolds are going to germinate quick or not at all. I grow some cosmos and i don't even bother getting them started I sow them where I want them. Never had a problem with those coming up. I would think marigolds are the same way.

Some seeds can take a long time. Real hard seeds need to be nicked and soaked over night or some of them can take years.