Overview of the Border Forsythia:
You know spring is just around the corner when the border forsythia bursts into bloom. This shrub is famous for being one of the earliest shrubs to flower each spring, adding cheery yellow blossoms to a yard that may be otherwise dulled by winter.
Border forsythia is Forsythia x intermedia. It resulted from a cross between Forsythia suspensa (weeping forsythia) and Forsythia viridissima (green-stem forsythia.
The Forsythia genus name was chosen in honor of a Scottish botanist named William Forsyth.
These shrubs belong to the Oleaceae (olive) family. Examples of other plants in this family include ash trees (Fraxinus spp.), jasmine shrubs and vines (Jasminum spp.), fringe tree (Chionanthus virginicus), privets (Ligustrum spp.) and the common lilac (Syringa vulgaris).
The names for this shrub include forsythia, border forsythia and golden bells.
Preferred USDA Hardiness Zones:
Border forsythia can be grown in Zones 4-8. However, flower buds may be damaged by frosts in Zones 4 and 5. Choose varieties like 'Ottawa', 'Northern Gold' and 'Meadow Lark' that can provide better flower bud hardiness.
The parents of this hybrid come from China.
Size & Shape of the Border Forsythia:
This plant grows to be 8-10' tall and 10-12' wide. 'Arnold Dwarf' and 'Courtasol' are varieties that will stay around 3' tall.
Growth is produced in an irregular shape, which can be tamed to some degree through pruning.
Forsythia can be planted in full sun or part shade. Full sun is the preferable choice to ensure the best possible floral show and growth.
Foliage/Flowers/Fruit of the Border Forsythia:
The lanceolate leaves are 3-5" long and feature tooths on part of the margins.
They are medium to dark green in spring and summer, fading to a lighter green or yellow-green in the fall. ‘Fiesta’ and ‘Golden Times’ feature variegated leaves. 'Evergold' and 'Gold Leaf' have yellow leaves. Some varieties like 'Lynwood Gold' and 'Spring Glory' turn purple in the fall.
The bright yellow flowers with four petals are the main attraction on this shrub. You will see them unfurl before the leaves do. They are formed in clusters on the stem.
After pollination, small brown capsules are produced. They do not add much to the appearance of the shrub.
Design Tips For the Border Forsythia:
This shrub will definitely brighten up a yard in the late part of winter and early spring, but will be rather ordinary and boring for the other seasons.
This can be planted in masses, screens and shrub borders. Forsythia can also be trained as a tree or hedge.
Growing Tips For the Border Forsythia:
Forsythia shrubs can handle the range of pH conditions from acidic to alkaline. Soil should be well-draining.
Drought can be tolerated if the root system is developed.
If your soil is poor, it can be helpful to add some organic matter like compost. Fertilizing yearly in the spring can help keep the plant healthy.
Cuttings are used to propagate this plant.
You need to prune this shrub right after flowering has ended as the buds for next year's flower show begin developing later in the year. Follow the pruning rule of 1/3 for shrubs and remove older branches.
Forsythia will produce suckers, so plan on pruning them away for a neater appearance.
Pests & Diseases of the Border Forsythia:
This shrub is almost always free of pests. You may find the red-banded leafhopper (Graphocephala coccinea) once in a while.
- Bacterial blights and cankers (Pseudomonas syringae pv. syringae)
- Crown gall
- Leaf spot
- Phomopsis gall (Phomopsis spp.)