Many of the pereennials we choose to keep in our yards are selected for their beautiful flowers. Whether we're adding a spash of color to a border area of our yard or building a complex web of colors in our gardens, perennials offer just what we need. Once we have one that we really like, we often want to add more of the same variety. There are several ways to propagate perennials, for this blog entry, I'm going to talk about seed propagation.
Flowers exist to make seeds. That's what they're for as far as the plant is concerned. Bright colors or attractive scents are just tools to make the flowers better at producing seeds. Color and scent attract pollinating insects or birds to fertilize the flowers by transferring pollen from the anther to the stigma of either a different flwoer or within a single flower.
Once a flwoer is pollinated in this way, the pretty petals are no longer useful to the plant so the plant stops using up energy to maintain them. The dry up and fall away leaving behind the grwoing seeds. Seeds may either be encased in some sort of pod, as in the California poppy or may grow individually as they do in the cone flower. In any case, once the flower dies off, the plant diverts energy to the growth of the seeds themselves.
Gardeners who want the plant to continue flowering for a longer period of time can make the decision of where to send energy for the plant. By cutting off the flowers as they begin to fade and wither, a process called dead-heading, the gardener can stop the plant from expendign it resources on seed growth. Instead, many plants, detecting the lack of viable seeds, will rush to produce more flowers to start the seed-producing process all over again before autumn sets in.
Those who want to gather seeds from their perennials to produce even more plants next year, therefore, should not dead-head the spent flowers. Even though more flowers might grow later, the plant should have more energy earlier in the year and the first batch of flowers and seeds should mature faster and be more prolific and hardy.
When the seeds look all dried up they are ready to harvest. For those growing in pods like the iris or poppy, the top of the pod may "pop," providing a way for the seeds to exit the pod. Collect the seeds and carefully label them if you are going to save them until spring planting or start them indoors.
Seeds collected from many perennial plants adapted for northern climates will not grow if planted indoors immediately or if kept indoors until spring. Think about it. If these seeds were ready to sprout as soon as they matured, most would start growing in the autumn after a late summer rain or during a warm week in late Spetember or October. This would mean the plants would be fragile and tiny seedlings when the frost and killing freeze hit them.
The would not have strong root systems or stores of energy saved up from rampant leafy growth phase that often occurs in the parent plant after the seeds have matured. In other words, they would not have the stregnth or energy to survive the winter and spring up again whne the ground thaws and the warm weather returns the following year.
Plants have adapted to the climate over millions of years and have solved this problem in a variety of ways. One of the most common ways that seed-producing plants in northern climates have overcome this obstacle is to produce seeds that will not sprout until they have been cold-conditioned, or spent some time in winter-like temperatures. Extended periods of cold are required to "prime" the seeds or trigger them to respond to favorable growing conditions.
Failure to cold-condition seeds harvested from garden plants is one of the main reasons for very low yields or complete lack of germination. Fortunately, armed with a little knowledge, gardeners can cold-condition perennial seeds to make them ready to plant.
This can be done in two ways. First, seeds can be cold conditioned the natural way. You can scatter or plant them in the fall before winter to allow them to be cold-conditioned by the winter termperatures. This will generally work fairly well. After all, if left to its own resources, it's how the plant would handle the matter itself. On the other hand, look at the number of seeds most plants produce and ask youself why your yard isn't completely overrun with wild flowers. Each poppy flower produces hundreds upon hundreds of seeds, but you don't wake up one spring morning to find five or ten thousand new poppy plants growing in your yard. That's because many of the seeds don't survive until spring.
Why not? Well, many reasons. Insects, birds, or rodents may eat them in the fall, the spring or even during the winter itself when other food is scarce for winter birds or those few rodents that don't hibernate. They may succumb to fungal infections or rot if they stay too wet for too long. They may be lying on top of the ground exposed to extrememly cold temperatures that test them beyond their cold-resistant properties. Perhpas they simply fall on a patch of ground that is not conducive to plant growth. Some few may even try to sprout without cold-conditioning, dooming them to an early demise.
Still, enough survive to ensure the continuation of the species, so leaving them to endure the winter can be a successful propagation strategy. The up side of this approach is that the seeds decide when to start growing in the spring. When the soil is warm enough, has the right level of moisture, and there is enough sunlight in the day to ensure the young seedlings have the best chance at survival, they will sprout on their own and begin to grow. This way, they are automatically hardened off to outdoor conditions.
To cold-condition perennial seeds this way, harvest the dried seeds from the plants in the fall or as soon as they are ready. Decide where you want them to grow next year. Clear other plants that may already be growing there so the new sprouts will have less competition form stronger more mature plants. This may means digging or pulling up roots as many wild perennials will propagate from even small pieces of root.
It doesn't have to be a perfect process, but the more of the existing plants that are pulled, the better chance the need seeds will have in the following spring. Then, after the first few frost, simply scatter the new seeds over the prepared plot. Do not water them in. Remember, the plan is for them to remain dormant until spring. All that water will do at this point is reduce the viability of the seeds.
The other method of cold-conditioning perennial seeds is to keep them in the refrigerator for at least 45 days. The refrigerator temperature is cold enough to convince the seeds they have made it through an actual winter. However, the danger of this method is dehydrating the seeds. The cold air of the refrigerator will suck every bit of mositure out of the seeds, killing them in the process.
To prevent this, pack them as you would pack food to prevent freezer burn. You can place them in a double-sealed freezer bag or an air-tight tupperware type container. You don't want too much moisture in the container or too much air. Once they have served their sentence in the fridge, the seeds can either be planted outdoors, or started indoors before it's warm enough to plant outdoors. Just remember that if you do start them indoors and want to transplant them outdoors, you'll need to harden them off, or gradually accustom them to the harsh rays fo the sun and the extreme hot and cold temperatures they may face once they are outside.
The second method, properly executed, should result in a much higher yield percentage for a given quantity of seeds. In other words, if 2-3 percent of the seeds survive and grow if left to fall from the parent plant and cold-condition in place, you might get as much as 80% or more germination from seeds harvested, cold-conditioned, and sprouted indoors.
Not all the perennial plants in your garden require cold-conditioning, but those well-adapted or native to northern climates likely will benefit.
Flowers exist to make seeds. That's what they're for as far as the plant is concerned. Bright colors or attractive scents are just tools to make the flowers better at producing seeds. Color and scent attract pollinating insects or birds to fertilize the flowers by transferring pollen from the anther to the stigma of either a different flwoer or within a single flower.
Once a flwoer is pollinated in this way, the pretty petals are no longer useful to the plant so the plant stops using up energy to maintain them. The dry up and fall away leaving behind the grwoing seeds. Seeds may either be encased in some sort of pod, as in the California poppy or may grow individually as they do in the cone flower. In any case, once the flower dies off, the plant diverts energy to the growth of the seeds themselves.
Gardeners who want the plant to continue flowering for a longer period of time can make the decision of where to send energy for the plant. By cutting off the flowers as they begin to fade and wither, a process called dead-heading, the gardener can stop the plant from expendign it resources on seed growth. Instead, many plants, detecting the lack of viable seeds, will rush to produce more flowers to start the seed-producing process all over again before autumn sets in.
Those who want to gather seeds from their perennials to produce even more plants next year, therefore, should not dead-head the spent flowers. Even though more flowers might grow later, the plant should have more energy earlier in the year and the first batch of flowers and seeds should mature faster and be more prolific and hardy.
When the seeds look all dried up they are ready to harvest. For those growing in pods like the iris or poppy, the top of the pod may "pop," providing a way for the seeds to exit the pod. Collect the seeds and carefully label them if you are going to save them until spring planting or start them indoors.
Seeds collected from many perennial plants adapted for northern climates will not grow if planted indoors immediately or if kept indoors until spring. Think about it. If these seeds were ready to sprout as soon as they matured, most would start growing in the autumn after a late summer rain or during a warm week in late Spetember or October. This would mean the plants would be fragile and tiny seedlings when the frost and killing freeze hit them.
The would not have strong root systems or stores of energy saved up from rampant leafy growth phase that often occurs in the parent plant after the seeds have matured. In other words, they would not have the stregnth or energy to survive the winter and spring up again whne the ground thaws and the warm weather returns the following year.
Plants have adapted to the climate over millions of years and have solved this problem in a variety of ways. One of the most common ways that seed-producing plants in northern climates have overcome this obstacle is to produce seeds that will not sprout until they have been cold-conditioned, or spent some time in winter-like temperatures. Extended periods of cold are required to "prime" the seeds or trigger them to respond to favorable growing conditions.
Failure to cold-condition seeds harvested from garden plants is one of the main reasons for very low yields or complete lack of germination. Fortunately, armed with a little knowledge, gardeners can cold-condition perennial seeds to make them ready to plant.
This can be done in two ways. First, seeds can be cold conditioned the natural way. You can scatter or plant them in the fall before winter to allow them to be cold-conditioned by the winter termperatures. This will generally work fairly well. After all, if left to its own resources, it's how the plant would handle the matter itself. On the other hand, look at the number of seeds most plants produce and ask youself why your yard isn't completely overrun with wild flowers. Each poppy flower produces hundreds upon hundreds of seeds, but you don't wake up one spring morning to find five or ten thousand new poppy plants growing in your yard. That's because many of the seeds don't survive until spring.
Why not? Well, many reasons. Insects, birds, or rodents may eat them in the fall, the spring or even during the winter itself when other food is scarce for winter birds or those few rodents that don't hibernate. They may succumb to fungal infections or rot if they stay too wet for too long. They may be lying on top of the ground exposed to extrememly cold temperatures that test them beyond their cold-resistant properties. Perhpas they simply fall on a patch of ground that is not conducive to plant growth. Some few may even try to sprout without cold-conditioning, dooming them to an early demise.
Still, enough survive to ensure the continuation of the species, so leaving them to endure the winter can be a successful propagation strategy. The up side of this approach is that the seeds decide when to start growing in the spring. When the soil is warm enough, has the right level of moisture, and there is enough sunlight in the day to ensure the young seedlings have the best chance at survival, they will sprout on their own and begin to grow. This way, they are automatically hardened off to outdoor conditions.
To cold-condition perennial seeds this way, harvest the dried seeds from the plants in the fall or as soon as they are ready. Decide where you want them to grow next year. Clear other plants that may already be growing there so the new sprouts will have less competition form stronger more mature plants. This may means digging or pulling up roots as many wild perennials will propagate from even small pieces of root.
It doesn't have to be a perfect process, but the more of the existing plants that are pulled, the better chance the need seeds will have in the following spring. Then, after the first few frost, simply scatter the new seeds over the prepared plot. Do not water them in. Remember, the plan is for them to remain dormant until spring. All that water will do at this point is reduce the viability of the seeds.
The other method of cold-conditioning perennial seeds is to keep them in the refrigerator for at least 45 days. The refrigerator temperature is cold enough to convince the seeds they have made it through an actual winter. However, the danger of this method is dehydrating the seeds. The cold air of the refrigerator will suck every bit of mositure out of the seeds, killing them in the process.
To prevent this, pack them as you would pack food to prevent freezer burn. You can place them in a double-sealed freezer bag or an air-tight tupperware type container. You don't want too much moisture in the container or too much air. Once they have served their sentence in the fridge, the seeds can either be planted outdoors, or started indoors before it's warm enough to plant outdoors. Just remember that if you do start them indoors and want to transplant them outdoors, you'll need to harden them off, or gradually accustom them to the harsh rays fo the sun and the extreme hot and cold temperatures they may face once they are outside.
The second method, properly executed, should result in a much higher yield percentage for a given quantity of seeds. In other words, if 2-3 percent of the seeds survive and grow if left to fall from the parent plant and cold-condition in place, you might get as much as 80% or more germination from seeds harvested, cold-conditioned, and sprouted indoors.
Not all the perennial plants in your garden require cold-conditioning, but those well-adapted or native to northern climates likely will benefit.
