Skimmia japonica
crop cultivation advice

General cultivation information, recommendations, tips & tricks

Best practice, suitable products and more for your Skimmia japonica

  • Skimmia japonica is a difficult crop to cultivate in high quality. The crop is produced mainly for trading in the weeks before Christmas. The cultivation is aimed at robust plants with many flowers.

  • Skimmia grows once per year. Branching in spring is crucial for flowering in autumn. The most important cultivar is Skimmia japonica ‘Rubella’. It takes 2 years to grow adult sellable plants from the cuttings.

  • Skimmias need soil with pH 4.8-5.3 (depending on local requirement). The EC should be generally kept at 0.6 mS indoor and around 1.0 mS for outdoor. The substrate should be always moist and with good buffering capacity and well drained.

Skimmia japonica is a difficult crop to cultivate in high quality.
The crop is produced mainly for trading in the weeks before Christmas.

Stage 1: Cuttings and young plants

Make the cuttings in June from a mother plant kept outdoor and shaded. Good nutrition of mother plants is important. Start propagation when the axillary-buds are visible. Use only hard, inflexible twigs for the cuttings. Pruning young plants is the key for a good plant design. Prune Skimmias individually to achieve the best results. Ensure high nutrition in the weeks before cutting mother stock. With cuttings in large cups you can mix 1 g/l Osmocote Exact Protect 5-6M through the substrate. When the cuttings starts rooting use 3 g/l Peters Professional Plant Starter 10-52-10. During the phase of branch growth apply 10g/m2/week Peters Excel Plant Finisher or CalMag Finisher. One week before potting add 5g/m2 Peters Professional Plant Starter 10-52-10.

Stage 2: Vegetation

Finishing potting before winter is crucial to allow for a good root development during the winter (in greenhouse). Skimmia’s roots are sensitive to salts. Control the EC levels in the pots, especially in high temperatures and during the flowering phase. Prune the plants before 20 June or they will not develop flowers in time. Apply crop protection preventively rather than curatively. Pot in November in a substrate with 4 g/l Osmocote Exact Protect 12-14M. Do not add water soluble fertilizers. Start in February with 5 g/m2 Peters Professional Plant Starter 10-52-10 to support the roots. Continue in spring period with 10-15 g/m2/week Peters Professional Blossom Booster 10-30-20 to support the flower development. From May the flowers have to grow and stretch: 15-20 g/m2/week Peters Professional Grow Mix 21-7-21 and CaNO3 supports this growth.

Stage 3: Finishing stage C2-3l pots

The August – September period is important for the maximum flower bud development in Skimmia. These buds will flower in spring the following year. Intensify the nutrition by irrigation during the late summer to build up necessary nutrient supply. Use mainly a high K schedule to avoid re-growth in the flowering phase. End in Autumn period with 15 g/m2/week Peters Excel Plant Finisher 15-5-30.

Products

Use different products for each cultivation stage

Product name
N
P2O5
K2O
More nutrients
Longevity

Osmocote Exact Protect 5-6M features a second (DCT) coating which delays release time by four to six weeks, saving nutrients until your plants can use them effectively. Ideal for salt-sensitive crops, Calluna spring pottings, and unrooted cuttings potted in end pots. Longevity is five to six months.

Peters® Professional Plant Starter gives your plants the perfect start in life, so they form stronger, more uniform roots. Also great for stimulating flower bud development.

Peters® Professional Plant Finisher provides optimum nourishment during the final stage of propagation as the finishing touch for maximum results.

If you irrigate with soft water, Peters® Excel CalMag Finisher is developed especially for you. It’s the perfect step on from Peters® Excel CalMag Grower 15-5-15 to ensure your plants flourish, all from one tank. They’ll be more compact thanks to the high potassium formula. And with plenty of chelated trace elements and a continuous supply of calcium and magnesium, they’ll achieve perfect color and growth. The M-77 chelating complex ensures maximum availability and absorbability.

Product name
N
P2O5
K2O
More nutrients
Longevity

Peters® Professional Plant Starter gives your plants the perfect start in life, so they form stronger, more uniform roots. Also great for stimulating flower bud development.

Peters® Professional Blossom Booster is a high-quality fertilizer that is specially formulated to promote bud formation and development.

Peters® Professional Grow-Mix is a low-phosphate formula with a perfectly balanced N:K ratio to stimulate your plant’s growth.

Osmocote Exact Protect 12-14M is the ideal solution for your conifers and roses, plus bare-rooted plant and grafted material in autumn and winter pottings between mid-October and mid-January. Longevity is 12 to 14 months.

Product name
N
P2O5
K2O
More nutrients
Longevity

Peters® Professional Plant Starter gives your plants the perfect start in life, so they form stronger, more uniform roots. Also great for stimulating flower bud development.

Peters® Professional Blossom Booster is a high-quality fertilizer that is specially formulated to promote bud formation and development.

Peters® Professional Grow-Mix is a low-phosphate formula with a perfectly balanced N:K ratio to stimulate your plant’s growth.

Peters® Professional Plant Finisher provides optimum nourishment during the final stage of propagation as the finishing touch for maximum results.

Osmocote Exact Protect 12-14M is the ideal solution for your conifers and roses, plus bare-rooted plant and grafted material in autumn and winter pottings between mid-October and mid-January. Longevity is 12 to 14 months.

Q&A

  • Yes, propagation in January or February is also possible, but not optimal, because the plants will grow faster above the soil surface than under it. There is a big risk of leaf burn.

  • No, Skimmia prefers shade. Keep the plants out of direct sunlight.

  • The most frequent problems are caused by the larvae of Sciara fly to which Skimmia is especially sensitive as it roots during summer. Wine Weevil (Othiorhynchus sulcatus) affects mainly older plants. Other harmful insects include caterpillars, aphids and spider mites (Acari). The Skimmia plants are also very sensitive to stem rot and root rot caused by Phytophthora. Protect the plants by avoiding peaks in greenhouse climate, irrigation, and nutrition. We recommend applying protection preventively throughout the whole year.