Help your lilacs bloom this season
Agreat plant for the Antelope Valley is the lilac. If you have lilacs, they are probably just finishing their bloom. Lilacs like our alkaline soils, cold winters and warm summers. They come in many different flower colors and range from small plants to very large plants.
The biggest disadvantage to lilacs is that they are deciduous, which means they lose their leaves in winter.
If your lilacs do not bloom this year, there can be several reasons. Lilacs will not bloom if they do not receive enough cold winter temperature. If you have lilacs planted too close to your home or in a warm location in your yard, they may not receive enough cold temperatures. Lilacs also prefer full sun and will have spindly yellowish growth with small to no bloom if they are planted in the shade.
The first step to ensure a good bloom next year is the proper pruning of lilacs. Most people think that winter is the best time to prune lilacs. If you pruned this winter, you have already removed a big part of the spring flower show.
Lilacs should be pruned immediately after they bloom, which should be now. Remove the stem that bloomed down to the point you can see new buds forming behind the leaves. These buds will be next year’s flowers. If you cut back farther, you can remove the flowers forming on your lilac for next years blooms.
When some lilacs are old and are not producing very much new growth, they do not form blooms. Without new growth, no new flower buds will form for next year. If your lilacs are overgrown or old, cut about a third of the oldest limbs all the way back to the ground. This will rejuvenate the plant with new growth and allow parts of the plant to flower. During the next two years, remove the remaining two thirds of the old branches.
The second step is to correctly fertilize your plants. If a lilac receives too much nitrogen, it goes into a growth cycle and does not flower very well. If the lilac is too close to a lawn, it may receive too much nitrogen when you fertilize your lawn.
When fertilizing lilacs there are several types of “bloom” fertilizers that help reduce the growth of plants and increase the bloom. Most “Bloom” type fertilizers do not contain nitrogen and have numbers on the label like 0-10-10 or 0-10-5. You are looking for a fertilizer that has a very low first number and high second and third numbers on the label. Lilacs like alkaline soil, just like we have in the Antelope Valley, so they normally do not need as much fertilizer as other landscape plants.
The last step is next fall, cut back the water on your lilacs to help ensure the plants go dormant during the winter. Most deciduous plants (plants that lose their leaves in the winter) that flower in the spring, need to go completely dormant in the winter. The main reason that plants will not go dormant in the winter is that they continue to get too much water in October and November.
Starting in late September, reduce the amount of water you are giving your lilacs in order to help them to go dormant. This can cause a problem in the landscape because the rest of the plants still need water. Lilac plants need to go dormant, so the flower buds will mature during the cold winter and form large full flowers the following year.
Cutting back the water is also important for flower bulbs. It is hard to reduce the water on plants in late summer, because the plants look wilted and lose their leaves, but that is what you want to do. Do not turn the water off completely in September.
Lilacs are not the only plant that should be pruned in spring after they bloom. Forsythia, flowering quince and lady bank roses are all best pruned after they bloom. In the case of lady banks roses, a good pruning job really improves next year’s bloom.
Lilacs are a great landscape plant for the Antelope Valley and come in many different varieties and flower colors. With their fragrant scent they can be a great addition to your landscape.