Special Seed Germination Tips
How to Stratify Chill Scarify Soak or Treat Seeds Before Planting
The secret to successful seed starting. Step by step instructions how to pretreat many flower and other seeds with special needs so they germinate and grow.
Most annual flower seeds will germinate and grow without special pretreatment, but many perennial flower seeds as well as tree and shrub seeds do have specific special requirements. Special seed treatments used prior to planting may include cold stratification, scarification, soaking in water, and -- less often -- acid or even exposure to fire prior to planting. Generally speaking, these treatments help to soften the outer seed coat to allow the seed to soak up water so germination will occur. Without correct conditions, your seeds will not grow so you need to be familiar with your plant's particular needs if you want to propagate a certain plant by seed. (General Instructions for Seed Starting Indoors.)
Research Your Plants for Special Seed Treatment Needs
Propagation by seed can be an economical and fun way to increase your plantings and can enable you to grow specialized plants unavailable by other means. If you want to propagate perennial flowers or woody plants by seed, do a little research and see which special treatment (if any) is recommended for the specific plant you want to grow. Your seed catalog or seed packet may give you directions on stratifying or other special conditions needed, or you may have to do some research. Skipping this important step can cause your seeding effort to fail, so take the time to check before you plant your seeds.
Cold Stratification of Seeds Before Planting
Cold stratification or chilling to mimic winter is the most common pretreatment for perennial flower seeds and for hardy tree and shrub seeds. Cold stratification or chilling can be accomplished by planting the seeds in autumn either outside in the ground, in a container outdoors, or in a cold frame so they undergo seasonal chilling outside. It can also be done using the home refrigerator. This is covered in detail with step by step instructions in How to Cold Stratify or Chill Seeds.
Seed Pretreatment: Seed Scarification
Another treatment you may come across is to scarify the seed, or scarification. This means roughen the seedcoat so it will absorb moisture better. (Seeds need to absorb moisture to grow.) You can do this by roughening the outside of the seed slightly with sandpaper, or by chipping or nicking the seed. To chip a seed, use a sharp knife such as a razor knife or scalpel and nick it or slice off a tiny bit of the hard outer layer of the seed. Some sources recommend piercing the seed with a pin but I have never been able to do this without stabbing myself. Don’t dig deep into the seed as this can damage the embryo inside; the goal is to slightly damage the hard outer layer of the seed.
Soak Seeds in Water to Pretreat
Another treatment you may hear about is soaking the seed in warm water overnight or until it swells and begins to burst open. To start, have the water hot to the touch (not boiling.) Place the seeds in a small container with the hot water and allow to sit and soak overnight at room temperature. Most seeds will be ready to plant within a day or two. Keep them soaking at room temperature. Change the water every day or it will sour; use tepid water for the change. Do not wait so long that they ferment. Do not let them dry out between soaking and planting.
Acid Treatment for Seeds
Acid treatment is occasionally mentioned, although more often for certain woody trees and shrubs rather than for flowers. Vinegar or sulfuric acid or gibberellic acid or occasionally urine might be the recommended acid, depending on the specific seed.
Fire and Seeds
One more really unusual treatment is fire. I have never seen it recommended for the more common garden flowers, but in nature it does happen.
The Difference Between Failure or Success With Seeds
Many otherwise viable seeds fail to grow due to lack of the appropriate pretreatment. I hope this gives you an understanding of the types of special conditions some seeds require before they will germinate and grow. Remember to research your plant and find out if the seeds need a certain pretreatment before planting . Most can be treated easily -- and a seed is a terrible thing to waste. Last but not least, if you are having trouble you may want to check the seed viability and here are instructions on testing seed viability.
Happy Gardening!
MORE FLOWER GARDENS ARTICLES and FLOWER GARDENS BLOGS, TOO
