Shrubs & Trees for Late Winter and Early Spring Forcing

from The Frelinghuysen Arboretum

The following table gives times to bloom for forcing branches of local trees and shrubs when cut at various dates.

Plant nameDays to Bloom
if cut on …
Normal
Bloom time

Expect

 1/282/153/15  
Abeliophyllum distichum – White forsythia20155April 5Flowers
Acer palmatum & japonicum – Japanese Maple2010April 5Flowers/leaves
Acer rubrum – Swamp or Red Maple20106April 5Flowers/leaves
Amelanchier arborea – Serviceberry, Shadbush252015April 15Flowers
Berberis spp. – Barberry157MayFlowers/leaves
Betula spp. – Birches20155March 25Leaves
*Cercis canadensis – Redbud2013May 5Flowers
Chaenomeles speciosa – Flowering Quince252010April 20Flowers
*Cornus florida – Dogwood22May 15Flowers
Cornus mas – Cornelian Cherry Dogwood20105March 25Flowers
Corylopsis glabrescens – Fragrant Winterhazel20105April 5Flowers
Forsythia x intermedia – Forsythia20105April 5-15Flowers
Hamamelis x intermedia – Witchhazel3-71-3Feb.-Mar.Flowers
Jasminum nudiflorum – Winter Jasmine105Feb.-Mar.Flowers
Lonicera fragrantissima – Winter Honeysuckle25155March 25Flowers
Magnolia stellata – Star Magnolia157April 15Flowers
Magnolia x soulangiana – Saucer Magnolia157April 15Flowers
Mahonia bealei – Leatherleaf Mahonia207March 25Flowers
Malus hybrids – Crabapples3020April 25Flowers
Pieris japonica – Japanese Andromeda20147April 15Flowers
Prunus spp. & hybrids – Ornamental Cherries251810April 20Flowers
Pryrus calleryana – Callery Pear2010April 15Flowers
Rhododendron mucronulatum – Korean Rhododendron205March 25Flowers
Spirea prunifolia – Prumleaf Spirea2212April 15Flowers
*Syringa vulgaris – Common Lilac20MayFlowers/leaves
*Viburnum carlesii – Koreanspice Viburnum207April 20Flowers
*Weigela floribunda – Weigelia – 25 15 May 10 Flowers2515May 10Flowers

*These may be more difficult to force. Keep humidity high by missing daily and/or cover branches with a plastic bag.

Cut branches should be soaked for a few hours to overnight in warm water. The easiest way to do this is to lay branches in a bathtub. Place branches in a clean container and fill with warm water, adding a floral preservative to keep prevent bacteria from forming. About every fifth day, thoroughly clean container, fill with fresh water and give the branches a new cut before placing them in the water. To clean the container, fill with warm water and ¬Ω cup of bleach. Let the container soak about one hour, drain and rinse well before refilling.

The closer you get to the normal bloom time the faster the branches force. Please note that in warm years, plants will force much easier than in really cold winters. The number of days given is an approximation and length of time may vary.