What you need to know to get healthy cuttings
Claire, Plantpassion
Growing from cuttings is one of my favourite types of propagation.
A cutting exploits the plant's ability to regenerate itself into a full blown plant from a piece of leaf/ stem or root. This happens because the cells in the sap-carrying tissue change, and become root cells, and then adventitious roots form from the wounded part.
It's that little bit more difficult, that it scares off most beginners, but most of the time if you know the key tips to getting healthy cuttings, they are an easy and very profitable way to multiply up your plants.
So for healthy cuttings you need:
Healthy stock plants - the parent plant needs to be in good condition and free of disease or virus.
Prepared growing medium - this will depend on the type of cutting being taken, but generally you need a mix that has small particles, so sieving may well be worthwhile. Plus it needs a free draining composition. I often add vermiculite to my cutting mixes.
A suitable sheltered position for the cuttings to root and establish. Some will need bottom heat, whereas some will just need to be placed out of wind, sun and disturbance.
Sharp clean blade for taking the cutting.
For me the most important thing that I find helps my rooting rate is for the growing medium to be prepared and ready to be planted into before I take the cutting materials.
My general cuttings method:
Prepare growing medium, sharpened knife, propagator, labels
Fill seed trays or pots
Make cuttings (and collect into a clean plastic bag if you’re away from the potting shed)
Dib holes and place cuttings in trays or pots - firm in.
Label and put in propagator
Water
Important note on propagating plant material
Plant Breeders Rights or Plant Variety Rights - some plants will have been registered by the breeder to prevent the propagation of the plant except under their control. In effect this includes propagation for any commercial gain including the sale of flowers from plants. Existing regulation applies in Europe and there are similar regulations in other parts of the world. Regulations cover seed, cuttings, division, and any other form of propagation.
Growing Chrysanthemums from cuttings
Chrysanthemum are often expensive to buy as plants and although they can be divided, you can actually get more new plants by cuttings. Commercial growers discard their plants when all the flowers have been cut, and buy in unrooted cuttings to start again each time.
Note some Chrysanthemums are covered by Plant Breeders Rights (PBR), so they can't be propagated for commercial use. In that case you will have to buy in cuttings. However a lot of older varieties, that are valued for autumn colour and long lasting, interesting flowers, are great subjects for taking cuttings.
I grow earlier flowering varieties in the ground outside, and later flowering varieties in the ground or in large pots in the polytunnel.
I dig up roots from the ground in autumn, and store them overwinter in pots in a greenhouse. I've found that they don't need to be frost free, as long as they are potted, kept on the dry side, and kept off the ground (I use cheap wire shelving).
As soon as spring growth starts, you can begin taking basal root cuttings. I've found that the majority of my cuttings are taken from the first week of March onwards.
Cuttings taken in Feb - April will grow multiple stems and flower that year. Cuttings can be taken in May to produce single stemmed plants that will flower that year, and can have cuttings taken from them for the following year. It is very important to only use healthy plants for cuttings of Chrysanthemums, as there are many viruses that could be transmitted, so check for yellowing leaves, and for signs of any pests such as red spider mite or leaf miner. Here's my method:
1) Prepare cutting mixture, fill trays and tamp down
2) Clean knife, and take a stem cutting abut 3 leaf joints from the tip. You want a large area that the roots will develop on, so cut at a diagonal angle at the leaf joint
3) Take off all but the top leaves, to ensure that energy is put into creating roots rather than maintaining leaf health. Quickly to ensure that the cut doesn't dry up, dib a hole in your growing medium and insert cutting
4) Press down cutting into growing medium, so that the compost is in contact with the wound, and there are no air pockets
5) Label, put on heat if available, wait for roots to form
Growing Dahlias from cuttings
The vast majority of dahlias for showing in the UK are grown from cuttings. To get plants from a cutting to a large enough sized plant to produce show quality flowers, in one season, does take specialist growing propagation units and concerted feeding and watering routines.
For those of us who don't need show sized dahlia heads and are are looking to multiply up our favourite dahlia varieties, or those that are difficult to get hold of, then taking dahlia cuttings is a great method.
For show dahlias you need to put your tubers on heat in January. This means that you can start to create cuttings from mid February, and will have pot sized plants to put in the ground when the risk of frost has passed, at the end of May or beginning of June in the north of the UK.
Unlike chrysanthemums where the cutting material comes from basal shoots from beneath the growing medium, dahlia tubers produce their new shoots and therefore cutting material, from the stems. So dahlias do not need to be completely covered in the growing material to produce new shoots.
Just like chrysanthemum cuttings though, you need clean materials, and ready prepared trays.
It was with dahlias that I learned how important this is.
My first year, I couldn't afford as many dahlias as I would have liked. However I wasn't worried, as I'd taken cuttings before in my greenhouse at home and I knew it wasn't too difficult, which would mean I could bulk up my numbers, and have more the following year. So as we planted out the first plants, I took cuttings off each plant, and dibbed them into trays. However this meant that we weren't taking them out to the field very fast for planting, and I only had help that day for a couple of hours. So when I'd finished the first tray of cuttings, I took a whole trolley of dahlia plants out to the field, and placed them for my team to plant, and took cuttings as I was placing them, and put them in a plastic bag (That's always what they do on Gardeners World). By the time I got back to the polytunnel it was 20 minutes later. I filled my 2nd seed tray, and dibbed in the cuttings from the bag. Both trays were put in the same place. From the first tray I had an 80% success rate. From the 2nd, where the cuttings had 20 minutes to dry out in the bag, I had about 20%.
Here's a You tube video I made last season about taking cuttings
(The burnt orange dahlia that wasn't what it was labelled as was Nicholas, and I now have an extra 8 tubers that grew / flowered very well last year and will be split this year)
Root cuttings
Root cuttings are a less used, but an extremely productive method of taking cuttings to multiply up stock.
This works best where plants have rubbery roots that have nodes, and rootlets coming from each node.
Mint is a wonderful example.
A root like this is easy to spot where to divide, I'm always astonished how quickly plants will grow from 2-3cm pieces of root.
My key plants that I use this method for are:
Mint
Lemon Balm
Acanthus
Papaver orientale
Paula’s tip: Lysimachia
Carol’s tip: Anemone huphenesis
Other cut flowers from cuttings
Penstemons - stem tip cuttings. Take cuttings in July, and they'll root within 4 weeks, and flower the following year.
Scented Pelargoniums - stem cuttings. Take cuttings in Autumn, and keep in a heated greenhouse or inside over winter. Ensure you take off all but the top leaves. Alternatively keep plants frost free, and take cuttings from new growth in spring.
Hydrangea - soft wood cuttings. Late summer is the best time to take these, and if given base heat will root in a couple of months. They need to be potted on a couple of time and shaped before planting out.
Privet - semi ripe cuttings. Side shoots of Privet provide heel cuttings in summer that will root in well drained compost.
Delphinums - basal stem cuttings. In a similar way to Chrysanthemums, any potted up Delphinium will produce some shoots at the base which can be used as cuttings. These will need heat to root, and are susceptible to rotting off, so ensure correct watering, and well drained compost.
Rosemary and Sage - heel cuttings. Easy to take late summer, and will root easily.
Salix - Willow - hardwood cuttings - Take cuttings in winter, February is best, you can get several cuttings out of each Willow shoot, so ensure the bottom cut is made at an angle, and the top is straight across, so you know which way up to plant.
Dianthus / Carnations - heel cuttings - These are easy, and can be peeled off the main stem. Do take off some of the other leaflets, so there isn't too much top growth while they are forming roots.