Starting garden vegetables from seed is easy and cost effective – plus you’ll find pages upon pages of varieties and cultivars in catalogs and online! To ensure your seed starting is successful, avoid these 8 common seed starting mistakes.
- Starting Seeds at the Wrong Time. Timing is everything when it comes to growing from seed. Whether you are starting indoors or direct sowing into the garden, it’s critical to know your region’s last average day of frost. For north Idaho it’s May 15th. Warm season crops should be started indoors 6 to 8 weeks before this date.
That means now is the time to start tomatoes, eggplant, and peppers indoors. If these are started from seed in late April or May, they may not have enough time to mature and produce fruit in the garden. Cool season crops can also be started indoors now and transplanted into the garden in just a couple of weeks — usually 2 to 3 weeks before May 15th.
2. Using Inferior Growing Medium. Don’t go cheap on your growing medium. This is the foundation for your plant stock. To get your seeds off to a good start, choose a quality soil-less seed starting mix. These are usually a mixture of peat, coconut fiber, and perlite. The consistency is very light and fluffy. Avoid potting soil mixes that contain fertilizer – nature packs seeds with all the nutrients they need to get started. And finally, never use soil from your garden – it’s too heavy, won’t drain well, and may contain disease or insect eggs that can affect your tender seedlings.
3. Starting seeds in cold, wet soil. Seeds need warmth to germinate. A few days before planting, bring your seed mix into the house and warm it up. If the mix is dry, this is also a good time to add a cup or two of water to lightly moisten the mix. Let the mix come up to the ambient temperature in your house before planting. Once seeds are planted, use a heat mat to help move germination along and aim to keep soil temperature in the 65 to 70 degree range.
4. Planting Seeds Too Deep. Most seeds can be placed on the starting mix surface and covered with a ¼ to ½ inch of mix. Some seeds need light to germinate (like lettuce) and should be scattered on the surface and not covered at all. If seeds are planted too deep they may not germinate. I like to dampen the soil in the growing container first, then place the seeds on the surface and spray the seeds with a fine mist of water from a spray bottle (warm water, of course!). Finally, I lightly cover the seeds with mix and spritz the soil again. This ensures good seed-to-soil contact and helps soften the seed coat.
5. Not Labeling Growing Containers or Trays. Guilty! How many times have I done this? I’m not telling, but suffice it to say, anytime you see a “Mystery Tomato” sign at my Farmers’ Market booth, you’ll know I’ve done it again. It happens – you’re excited to get growing and before you know it you’ve planted three kinds of seed and you don’t know which is which. Seeds of a variety look alike and so do the seedlings! Plan ahead…grab a Sharpie and a plant tag, wooden stick, or address label and tag those containers or trays!
6. Not Enough Light. Seedling need bright light to grow. In fact, they need about 12 to 16 hours of light per day. Your sunny window may not provide enough light to get them off to a good start. An inexpensive LED fluorescent shop light will provide all the light your plants need. Make this easy and put your light on a timer. For stocky and healthy plants, place the light about 3 inches above the seedlings. No more scraggly, leggy seedlings!
7. Too Much Water. This is probably the #1 mistake in seed starting. Keep your seedlings moist, not wet. Too much water causes a fungal condition known as dampening off – seedlings will rot at the soil level and die. Let the soil surface dry a bit – it’s much better to be a little dry than too wet. No baby wants a soggy bottom.
8. Not Giving Seedlings Enough Attention. And speaking of babies, that is exactly what seedlings are and need to be treated as such. Young plants, like young humans and animals, require a lot of attention. Check on your seedlings several times a day to monitor moisture, temperature, and any signs of distress, disease, or insect issues. They won’t survive on their own and will quickly perish if neglected. We now know why garden centers are called “nurseries!”