Plants are expensive. Whether you’re picking up a seedling six-pack or a new houseplant from the greenhouse, the costs add up. But what if you could expand your garden at only a fraction of the cost? That’s where plant propagation comes in.
Plant propagation is the process of creating new plants through sexual or asexual propagation methods. Seeds are the most common method, but you can also propagate perennials through cuttings, layering, division, separation, and grafting.
However, it is important to remember that plant propagation takes time, knowledge, and skill. That’s why seedlings and plants cost a lot more than a packet of seeds – you’re paying for someone else’s time and expertise. Each propagation method has a learning curve to master, and for most plants, only one or two methods may even be effective.
That being said, while many methods seem intimidating, all gardeners can learn at least a few methods, and it can be quite satisfying knowing that you grew this rosemary bush from just a cutting.
Ready? Let’s begin.
Hey – you can get our weekly gardening newsletter here!
Join 1000+ gardeners to get access to news, tips, and information.
Delivered right to your inbox – once per week.
Plant Propagation Methods
Plant propagation is either sexual or asexual.
Sexual propagation is propagation by seed. Two parent plants give their genes to a new plant. The new plant can display characteristics from one or both parents.
Asexual propagation is every other propagation method, including propagation by cuttings, layering, division, and grafting. You’re taking a part of the parent plant and causing it to regenerate into a whole new plant. The new plant is genetically identical to the parent.
Image courtesy of: Carrivard via Wikimedia Commons https://commons.wikimedia.org/wiki/File:Tomato_graft_union.jpg
Propagation By Seed
Propagating by seed is the easiest and most prevalent propagation method, both for home gardeners and in nature. Most annual and perennial plants propagate best by seed. Seeds can be heirloom, open-pollinated (OP), or hybrid (including F1).
Open-pollinated plants (OP) reproduce true to type, so when you collect seeds from an open-pollinated plant, you’ll get a plant with similar traits to the parent plant.
Heirlooms are open-pollinated plants that home gardeners and plant breeders have developed, grown, and passed down for over 30 years.
Hybrids are seeds that have been cross-pollinated with another variety or species, but if you collect seeds from a hybrid plant, the resulting plant won’t be the same as the hybrid parent.
Hybrids occur naturally (for example, if you planted those squashes too close to your cucumbers), or they can be deliberate. All heirloom seeds started off as hybrids, but through generations of breeding, now reproduce reliably.
F1 seeds are first generation hybrids, usually bred by commercial seed growers, for certain characteristics and better resistances.
Hey – you can learn about our seed starting course here!
Learn what you need to know so you can start plants from seed!
Over 1 hour of video content on seeds – from start to finish.
Advantages To Propagation By Seed
- Readily available to gardeners in stores, by seed catalog, by seed exchange, and by seed saving. You don’t need a parent plant to start a new plant from seed – you just need a seed.
- Can find more varieties with seeds than when buying seedlings, so you can find the best variety for your garden’s unique conditions.
- More resilience thanks to genetic diversity in open-pollinated seeds, meaning at least one plant may survive diseases, pests, drastic changes in weather patterns, and other stresses. If all your plants are genetically identical, they will all die. Collecting and preserving seeds in seed banks protects genetic diversity, and planting different varieties of the same species could save your garden from complete disaster.
- Easy to learn, although starting seeds inside has some learning curve.
- Saving your favorite open-pollinated seeds saves you money. You can also make new gardener friends through seed exchanges.
- You get to drool over seed catalogs, a favorite winter activity for many gardeners.
Disadvantages To Propagation By Seed
- Takes longer to propagate than by other methods, if other methods are available. Starting a new fruit tree from seed takes longer than grafting a fruit tree limb on a rootstock.
- Some seeds don’t germinate reliably, like lavender, thyme, and St Augustine grass. Seeds may need scarification (scratching the seed coat) or stratification (exposing the seed to cold temperatures for a period) to germinate, which can be hit or miss for gardeners learning these methods.
Propagation By Cuttings
Propagation by cuttings is cutting off a part of a perennial plant so that part regenerates into a new plant. The plant part used depends on the plant species and include:
- Stem cuttings are cutting off the stem using one of 6 different cutting techniques, such as Tip cuttings, Medial cuttings, and Cane cuttings.
- Leaf cuttings use a leaf and are only used for a few indoor plants, like begonias. Other plant leaves will just decay.
- Root cuttings are taken from plants that are at least 2 to 3 years old, and can reproduce from cut roots. The size of the cutting depends on whether the plant has large or small roots. Use a longer cutting for larger roots, and a shorter cut for smaller roots.
Image courtesy of user Kumar83 at Wikimedia Commons: https://commons.wikimedia.org/wiki/File:Stem_Cutting.jpg
To propagate by cuttings, cut off the particular part with a sharp, sanitized blade, remove any flowers or flower buds, and insert the cutting into a rooting medium like soil, water, or vermiculite.
Keep the rooting medium moist. Place stem or leaf cuttings in bright, indirect light. Place root cuttings in the dark until new shoots appear.
To speed up root growth, dip the cutting into a root growth hormone.
Advantages To Propagation By Cutting
- Best method to propagate most indoor plants and woody and herbaceous plants that germinate poorly.
- Faster to grow a new plant than from seed, as they’ll have a good head start with whatever part it’s regenerating from.
- You get an identical plant to the parent plant, rather than risking what may come from a seed. If you know someone with a plant that you love, you can propagate an identical plant from a cutting (but ask first!).
Disadvantages To Propagation By Cutting
- No genetic diversity, which may not be a problem with houseplants, but may pose a problem with outdoor plants.
- Takes some trial and error, especially if you’re not using a root growth hormone. You may only root 1 out of 6 cuttings at first.
- Best done at certain times of year, depending on the plant. Cuttings are best taken from woody plants in the fall or during dormancy.
Hey – you can get our weekly gardening newsletter here!
Join 1000+ gardeners to get access to news, tips, and information.
Delivered right to your inbox – once per week.
Propagation By Layering
Propagation by layering happens when a stem from a parent plant touches a rooting medium and forms roots. After the new plant is established, it can be cut from the parent stem.
Raspberry canes and mint are two plants that layer, whether or not you want them to.
Based on the plant, you’ll use one of 5 techniques:
- Tip layering is digging a small hole, inserting a shoot tip, and covering it with soil so the stem remains in the soil. You’d use this on raspberries and trailing blackberries.
- Compound layering is bending a flexible stem over the rooting material and alternately covering with the rooting material and leaving exposed sections of the stem. You’d use this on heart-leaf philodendrons and pothos.
- Mound layering is cutting back a plant to 1 inch above the ground when it’s dormant, then mounding soil over the emerging shoots in the spring. You’d use this on gooseberries and apple rootstocks.
- Air layering is slitting open the stem beneath a node and surrounding the wound with wet unmilled sphagnum moss. Once the plant grows roots into the moss, you can cut the plant off below the new root ball. You’d use this to propagate thick-stemmed plants like dumbcane and rubber trees.
- Simple layering is simple – just bend the stem to the ground, cover it with soil (allowing 6 to 12 inches of the tip exposed), and stake the exposed stem vertically to hold it in place. Used for plants like rhododendron and honeysuckle.
Advantages To Propagation By Layering
- High success rate. New plants get all the resources they need from the parent plant while the new plant grows roots.
- Air layering can fix leggy woody plants by creating a new plant from the leggy stem.
- Grows faster than propagating by cutting.
- Saves space when using air layering and mound layering, as neither needs pots.
- Allows you to propagate plants that don’t root well when using propagation by cutting.
Disadvantages To Propagation By Layering
- Not every technique can be used on every plant. Look up the best layering technique for your plant species before trying.
- May take longer than cuttings, depending on the technique.
- Most layering techniques take up space, as they need pots set at appropriate distances.
- While you can get multiple cuttings from one plant, most layering techniques will only give you one new plant at a time.
Propagation By Division & Separation
Division is propagating a new plant by dividing any additional crowns on a plant. A crown is the connective tissue that joins the root and stem of a plant while also storing carbohydrate reserves.
Some plants, like dahlias, irises, and strawberries, grow more than one crown. Use a sharp, sanitized knife when cutting off crowns to minimize injury.
Separation works in the exact same way, except that instead of crowns, you’re separating bulbs and corms. Separation works for plants like tulips and crocuses.
Like most asexual propagation techniques, division and separation are best done when the plant isn’t actively growing and the ground isn’t frozen.
Advantages To Propagation By Division
- Allows you to add more perennials to your garden without having to buy new ones.
- Refreshes older perennials [PDF]. Most perennials with multiple crowns only have 3 to 5 years where they look their best. For example, strawberries only produce well for the first 2 to 3 years. By dividing or separating them, you’ll grow new plants to revitalize the garden bed.
- Alleviates root congestion by removing additional crowns, bulbs, and corms, which can cause plants to not bloom as much or look as nice.
- Gives more room in flower beds. Plants grow and spread out. We gardeners often underestimate how quickly plants can spread and fill out a garden bed, and soon, the garden bed may be too congested for plants to grow well.
Disadvantages To Propagation By Division
- Only works on plants with multiple crowns, bulbs, or corms.
- Requires digging up plants.
Propagation By Grafting
Grafting is taking a part of one plant (a scion) and joining it to another plant (rootstock) so that they grow as one plant. Many roses and most fruit trees are actually grown via grafting branches onto a hardier root stock.
The scion and rootstock must be compatible for it to work, so you can’t just graft any two plants together. Grafted vegetables are a recent innovation that helps grow better tasting fruit with more resilience in greenhouses.
(You can learn about grafted tomato plants here).
Advantages To Propagation By Grafting
- Allows you to grow less hardy plants like fruit trees and roses in colder regions.
- Allows you to grow multiple types of a fruit on one fruit tree. Only have space for one apple tree? You can buy or graft an apple tree with 3 to 7 different kinds of apples growing on it.
- Allows fruit trees to grow much faster than if grown by seed, especially if the rootstock is a fast-growing species.
- Since apple seeds do not grow true to type (the resulting fruit could be good or could be terrible, but definitely won’t be the same as the parent tree), you can only get a consistent variety through grafting.
- Inside a greenhouse, grafted vegetables taste better, produce more, and resist infection better than non-grafted vegetables.
Disadvantages To Propagation By Grafting
- Grafting is a more difficult propagation skill to learn and can often result in failure as grafts fail to take.
- You need to take proper care of the graft for the next 1 – 2 years or the graft will fail to take. Stems from the rootstock must be gradually cut back over that time while the scion takes over, but not too quickly as that will shock the plant.
- Grafted vegetable plants are more expensive to buy than other seedlings, and because the technique is fussy, it’s not worth it for home gardeners without greenhouses or high tunnels, as they can grow tastier vegetables from seeds.
Conclusion
Plant propagation can be intimidating to get started with, as it takes time and a willingness to persevere through failures, but by picking the right method and experimenting, you’ll soon be propagating your own little plant babies.
You can learn other ways to get plants cheap (or free!) here.
To find books, courses, seeds, gardening supplies, and more, check out The Shop at Greenupside!
Hey – you can get our weekly gardening newsletter here!
Join 1000+ gardeners to get access to news, tips, and information.
Delivered right to your inbox – once per week.
If you want to read some of my most popular posts, check out the “Best of GreenUpSide” page here. Enjoy!
~Jonathon