R2104 4.2 Describe methods of vegetative propagation Flashcards
Materials used in growing media for propagation: General
What qualities are needed in the growing medium?
- Needs to provide a healthy and suitable enviroment
- Should be free from pests and disease
- Cuttings need good Air Filled Porosity - oxygen is essential for respiration
- Nutrients are not required for the rooting stage - only needed once cutting has rooted
Functions of growing media for cuttings (4)
- To hold cutting in place while it is rooting
- To provide mositure for cutting
- To allow gaseous exchange as base of cutting
- To reduce light penetration to the cutting base
Materials used in growing media for propagation: Peat alternatives
- For example coir and composted bark
- Coir - clean, light, easy to handle. Moisture retention good, easier to re-wet than peat. Good AFP.
- Bark - Some types are toxic - generally overcome on the composting process. Pine bark is perferred as it has few toxins. Has some nutrients and retains some mositure (needs more regular watering than coir). It has good AFP.
Materials used in growing media for propagation: Perlite
- Light, sterile, inert
- Excellent AFP
- Can help with moisture retention - particles for not absorb water but hold water on the rough surface
- Damp down before handling as it can be very dusty
Materials used in growing media for propagation: Sand / Grit
- Coarse sand and grit improve aeration and drainage
- Fine sand can reduce AFP
- Sand and grit contain no nutrients
- Considerably increase the weight of growing media
What is sticking?
Related to cuttings
Describes the perparation of the cutting material and subsquent insertion of cuttings into a container or open ground. The date of sticking is recorded as the starting point.
What is wounding?
Related to cuttings
1.Many semi-ripe and hardwood cuttings benefit from wounding
2.Bark is cut away from base of the stem to expose more of the cambium and encourage rooting
3.The wounded tissue is stimulated into cell division
4. e.g. Rhododendron
What is a heel cutting?
Related to cuttings
Heel cuttings are taken with an extra silver of last years wood still attached
Many evergreens and broad leaved evergreens benefit from this
Taking a heel cutting
Lavandula
Variant of semi-ripe cuttings
- Idenfity a healthy looking shoot about 10cm long and pull down and away from main stem
- You will end up with heel. If heel is too long trim it with a sharp knife
- Dip heel into hormone rooting powder
- Place cutting into soil with heel lowermost
Softwood cuttings: general details for what to look for when collecting
- Take young sections from current growth
- At least 5-10cm long with at least two leaf joints attached
- Firm but flexible shoots
- No flowers, fruits or seedheads
- No diseased or damaged parts
- Vulnerable to drying out so collect from well ater plants and likes a humid atmosphere.
- Remove most leaves to reduce water loss
- Susceptible to botrytis
- Best material come from first flush of spring growth
- Bottom heat often needed
Softwood cuttings: Pelargonium
- Take cuttings in later summer from strong leafy, non-flowering side shoots betweem 5015 cm long
- Trim below the leaf joint (node) and cut off foliage from the lower half. Apply hormone rooting powder to base
- Insert cuttings into growing media up to lowest leaf amd water well
- Cover with clear polythene bag or put in propagator
- New top growth indicates rooting - at this point pot up plants individually
Semi-ripe cuttings: General
- Taken from mid-summer to early autumn
- Usually from, side shoots or top of main stem
- Wood is beginning to harden so firmer than softwood cuttings
- Take shoots 50-10cm long
- Cut below leaf joint or node with a straight cut. Remove leafs from lower half
- Dip base in hormone rooting powder
- Insert 2.5cm deep in well drained pots in a clear polythene bag or cover propagating case
- Place pots in cool green house and shade from bright sunlight
Semi-ripe cuttings: Chamaecyparis
Comifer cuttings
- Cuttings from later summer to end of autumn
- Can take up to year to make roots
- Cuttings from upright growth will produce an upright plant
- Sideshoots will create a low spreading plant
- Chose small healthy shoots 7.5-10cm long
- Pull off gently from plant, removing a sliver of darker wood
- Or snip of a side shoot to make cutting
- Remove lower 3cm of foliage. Any foliage in contact with growing medium could rot
- Dip cut end into hormone rooting powder
- Insert cuttings round the edge of a pot with free draining compost
- Will not thrive in wet conditions. Mix 50% compost / 50% horticultural grit OR 75% perlite / 25% compost
- Water well
- Place in cold frame / polythene tunnels / heat propagator with bottom heat
- Cuttings should not be too dry or too wet. Shade on sunny days/ Remove any dead or diseased material
- Pot up and fully harden off before placing outdoors
Hardwood cuttings: General
- Take at end of growing season from autumn to spring
- Optimum time after leaf fall or before bud break
- Using sharp secateurs cut just above a bud at junction between current years growth and previous years growth
- Remove any large leaves and side shoots. Trim cuttings to about 20cm for large trees / shrubs or 5-8cm for smaller specimens
- Make an angled cut just above top bud and horizontal cut just below the bottom one
- Wound cutting and dip base in hormone rooting powder
- Place into free draining compost and water well
- Can also be inserted into a cold frame or directly outside
- Dig a narrow trench in well drained soil with one side vertical so that cuttings can stand upright.
Hardwood cuttings: Buddleja davidii
- Take cuttings in autumn just after leaf fall
- Select healthy stems of current years growth which has hardened
- Avoid very thick or very thin material
- Cut cleanly away from parent plant
- Aim for 5 nodes in each cutting
- Make top cut just above node, sloping away from it
- Make bottom cut straight just below node
- Insert in a āVā shaped trench in open ground, with top 1/4 above the ground spaced 10-15cm apart