Cross-Leaf Cuttings
Sometimes known as cross-section and leaf-section cuttings, this technique is often used to increase Streptocarpus x hybridus (Cape Primrose).
1 The day before taking cuttings, water the mother plant and allow excess water to drain. Sever a healthy leaf close to the base, place on a board, and cut into cross-sections 2in (5cm) wide.
2 Fill a seed tray with equal parts moist peat and sharp sand; pack to ½in (12mm) below the rim. With a sharp knife, form slits ¾in (18mm) deep. Insert the cutting’s base into the slit. Pack compost around it.
3 Gently water the compost. Allow the leaf’s surface to dry and place a transparent lid on top. When young shoots develop from the leaf, detach them individually (usually with part of the parent leaf still attached) and transfer them to a small pot. Small but established cuttings have a better chance of being repotted successfully than large ones.
Step-by-Step: Horizontal Cane Cuttings
Several thick-stemmed houseplants can be increased in this way, including dieffenbachias (Dumb Cane), dracaenas, and cordylines.
1 Water the mother plant the day before taking cuttings. Sever a strong, healthy stem at its base, trying not to spoil the plant’s shape.
2 Use a sharp knife to cut the stem into 2–3in (5–7.5cm) long pieces; each part must have at least one strong bud (they grow from leaf-joints).
3 Fill a 5in (13cm)-wide pot with equal parts moist peat and sharp sand; pack to ½in (12mm) below the rim. Press each cutting horizontally into the compost to half its thickness, with the strongest bud facing upward. Hold in place with pieces of U-shaped wire.
4 Lightly water the compost, allow excess to drain, and cover with a plastic lid. When shoots and roots develop, transfer them to individual pots.
Step-by-Step: Vertical Cane Cuttings
Several houseplants can be increased in this way, including yuccas and dracaenas. Sometimes these cuttings are known as Ti-log cuttings (a word of Polynesian derivation), although properly this name refers solely to Cordyline fruticosa, earlier known as Cordyline terminalis and Dracaena terminalis. These Ti-logs are widely sold as specially prepared cuttings, with their ends covered in wax. The following advice refers specifically to them.
1 Cut off the wax from the lower end, but leave the wax covering the top intact, as this prevents loss of moisture before the cutting forms roots.
2 Add a handful of equal parts moist peat and sharp sand to the base of a pot. Hold the cutting with the waxed end upward and pot it up so its base is 1 ½–2in (36–50mm) deep. Gently water the compost.
3 To encourage rapid rooting, put the pot and cutting in an opaque bag and place in gentle warmth. Check the compost every 10 days to ensure it is still damp. When shoots appear, remove the bag and slowly acclimatize the plant to a lower temperature. Later, usually in 2–4 weeks, transfer the rooted cutting to a larger pot.
Step-by-Step: Cactus Cuttings
Some cacti, especially those that form clusters, can be increased from cuttings taken in spring or early summer. Remember to wear gloves when taking these cuttings.
1 Use a sharp knife to sever a few stems from the plant’s base, taking care not to spoil its shape. Allow cut ends to dry for a day or so, then insert in compost.
2 Fill a small pot with equal parts moist peat and sharp sand; pack to ½in (12mm) below the rim. Use a small dibber to form a hole to a depth about one-third of the cutting’s length. Insert the cutting, pack the compost, and lightly water from above. When young shoots develop or fresh growth develops at the cutting’s top, transfer to an individual pot.
Step-by-Step: Small-Leaved Succulent Cuttings
Several succulents, such as echeverias and crassulas, have small leaves that can be removed and encouraged to develop roots.
1 Water the mother plant the day before taking cuttings. Select a healthy leaf and gently snap it off downward or sideways. Take several cuttings without spoiling the plant’s shape. Allow cut edges to dry for a day or so.
2 Fill a pot with equal parts moist peat and sharp sand; pack to ½in (12mm) below the rim. Add a dusting of sharp sand to the surface. Use a small dibber or knife to insert each cutting to about one-third of its length.
3 When young shoots and roots develop from a cutting’s base, it can be transferred to another pot.
Dividing
Dividing is a quick and easy way to increase houseplants with fibrous roots and several stems. Spring and early summer are the best times to divide them.
Step-by-Step: Dividing
1 The day before dividing a congested plant, water the compost, and allow excess to drain. Then, to divide, place a hand over the soil-ball and invert the pot. Sharply tap the pot’s rim on a hard surface so the pot and root ball separate.
2 Place the root ball on a firm surface and gently tease it apart into several substantial-sized pieces, making certain that each part has healthy roots, stems, and leaves.
3 Prepare a clean, dry pot, filling its base with compost. Position one of the new plants centrally in the pot, so that the base of the stems is about ½in (12mm) below the rim. Dribble compost around the roots, packing it in layers until ½in (12mm) below the rim. Tap the side of the rim to level the compost.
4 Water the plant from above by using a watering can with a fine rose. This helps to settle the compost around the roots of the newly divided plants. Place the plant in a location with light shade until it is established. By dividing a congested plant, several new plants can be produced.
Layering
This is an easy way to increase houseplants with pliable stems, such as those that trail or climb. Late spring and early summer are the best times to do this.
Step-by-Step: Layering
1 The day before layering a plant, water the compost to ensure stems are turgid. Allow excess moisture to drain. Fill a clean pot, packing moist peat and sharp sand to about ½in (12mm) below the rim.
2 Bend a long stem near a leafstalk and about 5in (13cm) from its end. This bend is not meant to sever the stem, but to constrict it so roots will develop at that point.
3 Use a small piece of U-shaped wire to secure the bent section of stem 1–1 ½in (25–36mm) deep in the compost. Pack
