Cleaning Seeds for Propagation
It’s essential to remove the flesh when collecting and save seeds. In addition to being a source of moisture and decay, the tissue often contains chemicals that discourage seed germination. While it’s easy to extract large seeds by hand, small fruits like raspberries, goji, and mulberries have tiny seeds that are difficult and time-consuming to remove.
In the wild, the consumption of fruit by birds and other animals removes the flesh via the animals’ digestive processes. Freed from the fruit, and surrounded by newly digested nutrients, the seeds are free to grow. While sifting through feces may be an effective way to gather seeds; I’m optimistic that we can avoid that.
What’s In A Growing Zone?
Hardiness zones are an attempt to match plants to the geographical areas in which they will survive.
In the last half-century, North America has adopted two systems for determining growing conditions; the USDA growing zones and the Canadian Plant Hardiness Index. While both methods use “Zones,” they differ in how they are determined. Knowing their difference can help you choose the best plants for your garden and provide insight into pushing what’s possible in your garden.
USDA Growing Zones and Extreme Minumum Temperatures
In 1960, the United States Department of Agriculture (USDA) created a series of plant hardiness growing zones based on the 30-year average annual extreme minimum temperature. [Read more…] about What Determines Plant Hardiness Zones?
What Are The Pros and Cons of Propagating Plants with Cutting vs Seeds?
The two most common ways to propagate plants are seed or vegetative cuttings (stem, root, leaf, or tissue culture). While seeds preserve genetic diversity and give rise to new varieties, vegetative propagation can clone and preserve existing varieties. Here are some pros and cons of seeds and cutting.
Seeds have parents and result from cross-pollination between two different plants or a single self-fertile parent. Each seed is the result of sexual reproduction and is genetically distinct from its parents and each other. Seeds that resemble their parents are said to “come true to seed.” While some plants come true to seed, others, like apples, rarely resemble their parents.
Pros of Seeds
- Seeds are genetically distinct from each other and their parent plants.
- Desirable traits can be selected via careful plant breeding.
- Seeds create and protect genetic diversity. Genetic diversity creates resiliency from climate, pests, and disease stresses.
- The random recombination of genes can yield new traits; desirable fruit, cold hardiness, etc.
- Seeds yield new cultivated varieties (cultivars).
Cons of Seeds
- Seeds are genetically distinct and are thus inherently less predictable than cuttings.
- Not all plants come true to seed.
- Difficult to control cross-breeding in an open-pollinated environment.
Vegetative propagation is the process of starting a new plant from a root, stem, or leaf of an existing plant and results in a genetic clone. Cuttings are most useful when trying to preserve specific traits such as growth habits or fruit quality. Since seeds are genetically distinct, the only way to maintain a cultivated variety is to keep it under continuous vegetative propagation. The original Granny Smith apple was a seedling discovered in 1868 and cloned to produce every Granny Smith apple tree in existence. The Annurca apple, a seedling of Italian origin, has been growing since the year 0079 due to continuous vegetative production.
Pros of Vegetative Propagation
- Vegetative propagation produces genetic copies of their parent plants enabling the preservation of cultivated varieties of plants that don’t come true to seed. Without vegetative propagation, cultivated varieties would be lost at the end of the original plant’s life.
- A single-parent plant can yield a large number of cuttings for propagation.
Cons of Vegetative Propagation
- Vegetative propagation reduces genetic diversity and can leave plants susceptible to shocks such as climate changes or the introduction of pests and diseases. The practice of propagating potatoes via tubers (instead of seeds) made Irland’s potato crops susceptible to potato blight.
- Some plants are difficult to propagate vegetatively.
Propagate a Forest with Shrubscriber.com
Do you want to learn more about plant propagation? Join the Shrubscriber community, receive seeds, and take the Community Propagation Course while supporting trees for school and community groups at the same time!
Is this plant self-fertile, or does it need a pollinator?
Do Baby Plants Have Parents?
Each Spring and Fall, I give tours of the Edmonton Urban Farm to elementary kids, and at one point, we usually find ourselves sitting in the strawberry patch and talking about flowers, fruit and seeds.
“Can anyone tell me what all of thiese tiny little dots along the side of the strawberry are?”
“Those are seeds!”
“That’s right! And what are seeds? What do they do?”
“They grow into plants!”
“They do! Seeds are baby plants. Let me ask you a strange questions. Do baby plants have parents?”
*uncertain and confused looks*
As it turns out, baby plants do have parents. A seed is the result of sexual reproduction in which pollen (male) from one flower comes into contact with the ovary (female) of another. Some plants have separate (imperfect) male and female flowers, while others have (perfect) flowers that contain male and female parts. To further complicate things, plants can be male, female, or both.
- Dioecious species have separate male and female plants—Ex, Hops, seabuckthorn, willow, poplar, honeylocusts, and arctic kiwi.
- Monoecious species have separate male and female flowers on the same plant—Ex, corn, birch, pine, hazelnut, and squash.
- Unisexual species contain perfect flowers
By definition, self-fertile plants are both male and female and are self-pollinating when pollen from their male organs can fertilize eggs in their female organs.
While self-pollinated seeds have a single parent, they will not be an exact copy (clone) of their parent plant. Clones are made by taking vegetative cuttings.
There are two main reasons why a plant is unable to fertilize itself. The first is whether the plant is male or female. While both male and female plants will produce flowers, only the female plant will produce seeds (or fruit). When this happens, it is necessary to plant male and female plants to create seeds or fruit.
To increase genetic diversity and decrease inbreeding, some plants’ (male) pollen is incapable of fertilizing its own (female) eggs. While this strategy may reduce the number of seeds a plant produces, it will increase the genetic diversity of those seeds by ensuring that they result from cross-pollination with another plant. An increase in variety increases the odds that some seeds will germinate and survive until reproductive maturity.
Plants that need a pollinator include:
- Any plant whose pollen and eggs are incompatible with each other.
- All species contain separate male or female plants (dioecious species).
The seeds that result from cross-pollination are a genetic cross between two parents. While this process is usually left up to chance (wind or bees), it is sometimes the conscious result of human intervention. Plant breeders use cross-pollination by collecting pollen from one plant to fertilize another to breed new plants with desired traits.
Propagate a Forest with Shrubscriber.com
Do you want to learn more about plant propagation? Join the Shrubscriber community, receive seeds, and take the Community Propagation Course while simultaneously supporting trees for school and community groups!