Climate and your garden

Now is a good time to make an assessment of the trees, shrubs, and perennials in our gardens

Are longer dry spells going to be the norm for the Pacific Northwest? A prediction is being made for it to continue at least into next year and possibly longer.  So now is a good time to make an assessment of the trees, shrubs and perennials in our gardens regarding the moisture that they needed during our dry spring and summer.  Some plants didn’t survive even with a weekly watering, and may have to be replaced with plants that are drought-tolerant or eliminated. A larger selection of plants which survive in arid conditions will be sold in local greenhouses in the future. Every gardener has decisions to make regarding climate changes and how we plan, plant and grow our ornamentals and vegetables.

Questions and Answers

What drought-tolerant perennials will provide colour in the fall?

Many perennials will grow in our dry summers and wet winters and even flourish. For healthy plants provide good quality soil with deep drainage, proper spacing and a mulch to retain moisture. New plantings will need more water until they are established. The perennials that are drought-hardy and can be seen in local gardens at the present time are: Rudbeckia ‘Goldstrum’ (black-eyed Susan); tall sedums, a succulent with pink flowers and ground cover sedums; yarrow in yellow to paprika shades; echinacea, a cone flower available in many colors; gaillardia or blanket flower in autumn shades; hardy salvias or sage in lavender, blue or violet; liatris, tall spikes in white to pink blooms; Shasta daisy; hollyhocks; goldenrod, the hybrid; garden phlox and at the foot of the flower garden many shades of heucheras are available. Several of the plants mentioned are available in dwarf heights and mildew-resistant such as the “David’ phlox.

Why do so many experts advise watering plants in the morning rather than in the evening?

There is a saying, “you wouldn’t go to bed with your feet wet, so why would your plants?” There are ‘pros and cons’ regarding the best time to water. Watering in the morning allows the plant to drink during the warm day, but could evaporate before soil absorption in hot sun. It is believed by some that evening watering will lead to dampness desired by molds and mildews.  We do get rain and dew in the evenings and at night so one would think there would be many plants affected by these diseases.  The loss of plants from mold and mildew could occur if drainage is poor, foliage is too dense and air circulation is poor. Watering should be done at the base of the plant. The decision remains with the gardener as to the best time for themselves and the garden.

I have acquired a pot of mixed succulents earlier this year. They have outgrown their pot and need repotting. Should I repot them or put them into a sunny garden bed?

If the succulents, such as ‘hen and chicks’, are hardy for this area they can be either pot or garden plants. They will grow in most any soil except for compacted areas where drainage is poor. If the plants are non-hardy like the echeverias, they will not survive at a temperature below 5C. When grown indoors the succulents require a cool room and bright light close to the surface of the leaves, otherwise they tend to get leggy, ruining a nice compact appearance.

When can I prune my white hydrangea?

Since the species of hydrangea is not mentioned, I will assume it is white hydrangrea of the panicle species, Hydrangea paniculata. They bloom on new wood and should pruned in the fall or early spring before sprouting new foliage and bud set.  The panicle species can be identified by a small, thin leaf with a rough texture and matt finish. For more info on identifying and pruning hydrangeas, an excellent site is www.hydrangreashydrangeas.com/identify.html.

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