Gardening Calendar
What zone are we in?
Gardeners use this information in plant selection. In our arid climate, soil type, wind and water availability are additional factors. The USDA Plant Hardiness Zone Map lists Wenatchee and East Wenatchee in zone 6A. This zone carries an average annual minimum temperature of -10° to -5°. Micro-climates on your property may create slightly different growing conditionst, and higher elevations will be colder and may push your property into zone 5B (-15° to -10°).
Sunset magazine also has developed a Western Climate Zone system. On this map, our area generally lies within Climate Zone 2. Higher elevations and a distance west of the Columbia River are in colder Zone 1.
March
Gardens and trees start to awaken this month as the air temperature rises and the soil warms. Some spring tasks have a wider window for completion, and others a more temperature-demanding schedule. Such tasks such as pruning are better completed while it is cooler before leaf-break, and others such as sowing cool weather crops are more successful when we fine-tune our planting date to soil temperature.
Though the beginning of the growing season varies each year, start with these average temperatures in March in the Wenathcee area and fine-tune for this particular year and your location. Chelan and Leavenworth will be later:
- March average high is 55° and average low is 31°
- March average soil temperature at 6 inches is 46°F
- Trees begin to awaken when the soil temperature at 6 inches is 43°F
- Last frost- May 1-10
While it is still cool, its time to prune.
- Tea and floribunda roses were pruned back to about 36 inches last winter to protect stalks from breakage during heavy snow fall. Now its time to prune them to their spring height of 12- 24 inches. Trim to an outside-facing bud, making the cut approximately one-quarter of an inch above the bud and at a downward angle. Remove at the ground level any broken, dead, or crossing canes.
- Prune fruit trees.
- Forsythia bloom heralds Spring in our area. Use this bloom time as a reminder to apply pre-emergent to lawns to prevent germination of crabgrass, purslane, oxalis, and spotted spurge.
- Perennials are beginning to emerge. Remove last year's dead growth before new leaves emerge. Winter mulch can remain until after all danger of frost.
- Cut back ornamental grasses to 6-12 inches.
- If the soil warms in a usual Spring, potatoes are planted Easter weekend.
April
- Many varieties of heather are in bloom this month. When flowers are spent, trim the stems back to green growth to keep the plant bushy. Avoid cutting into brown woody growth, as it may not regenerate.
- Early this month, spray for peach twig borer and coryneum blight. Apply only as directed per the schedule and the manufacturer's instructions. Also spray for adelgid on Douglas fir.
- Spray schedule for home garden cherries, also read about cherry and apple pests
- Spray schedule for home garden apple trees
- Last frost occurs May 1-10
- Wait until the end of April to mid-May to plant tender annuals and vegetables
- Harden off annuals and vegetables raised indoors before planting them in their summer location. Acclimate them slowly to the brighter light and wind of outdoors. During the day, move them outside and at night return them to a sheltered location, or indoors if frost threatens. Move them first outside into shade for several hours. Extend the time over a few days. Then over several days increase their sun exposure. This process may take 7-10 days. Read more about it.
- When you start irrigating, water deeply and not as frequently to soak roots and encourage deep growth, instead of frequently and not as deeply. Water early in the morning.
May
- When the soil temperature reaches 55°F, warm weather plants and seeds can be planted directly into the garden. Mother's Day is a good rule of thumb.
- When cherries start to turn from green to light yellow, begin your spray program using approved spray and timing to control cherry fruit fly.
- Prune early-blooming shrubs like forsythia and lilacs soon after they finish blooming and before they set new growth, which will carry next year's bloom. Deadhead primroses.
- Fertilize roses in early May
- Install supports on peonies
- Start new lawns or over-seed while the weather is cool.
- Fertilize container plants every two-three weeks.
June
- Increase water irrigation as the temperature rises and the humidity drops.
- Lawns use more water June 15-August 15. Watch for a color change to a blue cast to indicate when to water. Water deeply. Set several a tuna fish cans around the lawn and when they are full, turn off the irrigation. Water deeply to encourage deep roots and less frequently, versus frequently and less deeply.
- Sharpen mower blades for clean cuts.
- Set mower height to 2.5 - 3 inches. Longer grass shades the soil, encourages deeper roots and higher drought tolerance, and reduces weeds. Cut no more than 1/3 of the grass height each mowing.
- Pinch off faded blooms to encourage new flowers.
- Pinch chrysanthemums back every 6 inches of growth until July 4. They will be bushier and have more blossoms this Fall.
- Fertilize roses after the first blooms.
- Begin training indeterminate tomato plants. Staked tomatoes produce earlier than those sprawling on the ground. Pinching out suckers that sprout between the main stem and the leaves directs growth to the main stem and fruits. While this reduces yield, it produces larger fruit. Do not remove leaves that shade fruit and protect against sun scald. Read more about tomato culture.
July
- Continue to pinch off faded blooms to encourage new flowers on plants that rebloom.
- Tomatoes with black soft bottoms have blossom-end rot. It is caused by a calcium deficiency in the plant and is aggravated by fluctuating soil moisture. Apply a mulch to help maintain an even soil moisture. Tomatoes need 1 inch of water per week. Do not overwater, which can stimulate heavy leaf growth and cause blossoms to drop.
- Good watering methods help plants flourish. Check plants frequently and water long enough to get water to the root zone. Avoid overwatering and saturating the soil, which drowns the plant and encourages root rot.
- If fruit set seems low, "tickle" tomato blossoms and cross pollinate male and female squash family blossoms.
August
- Apply the last rose fertilizer by mid- August.
- Fertilize strawberries about August 15 for a good crop next year.
- Do not fertilize trees or shrubs, as it will encourage fresh growth that may not mature sufficiently to withstand winter temperatures.
September
- To encourage green tomatoes to ripen, pinch off the growing tips of tomato plants 30 days before the first frost. Expect frost by mid-October in the Wenatchee Valley, so pinch by September 15, and sooner in colder areas.
- Early to mid-September is a good time to seed new lawns.
- Cooler temperatures make this a good month to plant trees, shrubs and perennials. Their roots grow well and establish for a fast start next Spring.
- Spring-blooming bulbs can be planted this month.
- When all your garden is harvested, rototill or work in compost to enrich it for next summer. It will continue to break down and encorporate into the soil on warm days.
- Taper off on the frequency of watering as temperatures cool.