Miscellaneous propagation FAQs

How do I harden-off plants which have been recently propagated in the greenhouse?

If plants are being moved from one temperature to another they need to acclimatize slowly so that they suffer as little check as possible. In progressing from the greenhouse to the garden, plants need to be put in a cold frame as a sort of halfway house. For the first few days, keep the frame completely closed; then gradually apply a little ventilation, at first during the day only, until finally the glass can be removed completely. The plants are then ready for planting out.

As an inexperienced gardener I’m interested in trying my hand at plant propagation. Could you suggest a check-list of easy subjects?

The following are all easy to propagate by the various standard methods. Check with previous answers for details of technique.

SEED

Columbine (Aquiiegia), sown outdoors in late spring; pot marigold (Calendula), sown outdoors in spring or autumn; flame nettle (Coleus), sown in greenhouse in January-April; Persian violet (Exacum), sown in greenhouse in spring or autumn; Transvaal daisy (Gerbera), sown in greenhouse in March-April; polka-dot plant (Hypoestes), sown in greenhouse in spring; marigold (Tagetes), sown in greenhouse, February-April.

CUTTINGS

Softwood cuttings taken from new growth in spring and rooted under glass: chrysanthemums, dahlias, dianthus, fuchsia, busy-lizzie (Impatiens), regal, zonal, and ivy-leaved geraniums (Pelargonium), wandering jew (Tradescantia).

Semi-ripe cuttings taken from growth just starting to turn woody in summer and rooted in cold frame: berberis, cotoneaster, elaeagnus, erica, hebe, hydrangea, honeysuckle (Lonicera), potentilla, syringia.

Hardwood cuttings taken from mature woody growth in winter and rooted outdoors: dogwood (Comus), deutzia, privet (Ligustmm), flowering currant (Ribes), willow (Salix), tamarisk (Tamarix), weigela.

Leaf cuttings taken in summer when plant is in active growth: begonia (B. rex and B. masoniana), sinningia (Gloxinia), mother-in-law’s tongue (Sanseuieria), cape primrose (Streptocarpus).

Root cuttings taken when plants are dormant in winter and rooted in cold frame: anchusa, aralia, eryngium, limonium, phlox, drumstick primrose (Primula dentata), stag’s-hom sumach (Rhus typhina).

LAYERING

Done with new growth in spring and summer, outdoors: clematis, dianthus, erica, jasmine (Jasminum), honeysuckle (Lonicera), Virginia creeper (Parthenocissus).

DIVISION

Done outside in autumn or spring: herbaceous perennials, erica, rose of Sharon (Hypericum), kerria, pernettya, butcher’s broom (Ruscus).

OFFSETS and RUNNERS

Naturally produced, can be removed and transplanted when large enough: spider plant (Chlorophytum), mother-of-thousands (Saxifraga stolonifera), house leek (Semperuiuum), pick-a-back plant (Tolmiea), urn plant (Vriesea).

How are plants cloned, and what are their advantages? Plants produced this way are always slightly more expensive, and I often wonder if it is worth paying the extra cash.

A clone is a group of plants which originate from a single specimen, which has been grown from seed or produced as a mutation from another plant. Cloned plants can be reproduced only by vegetative means, such as cuttings, layers, and grafts; and every plant is identical to its parent. Plants are cloned because they have desirable characteristics which are better than those in other available varieties and which cannot be passed on through the seeds.

Sorry, comments are closed for this post.