Whether or not to prune your Hydrangeas — and how to prune them — is one of the most common questions our service department receives. We’ll try to simplify the answer for you below.
Old wood or New wood?
Hydrangeas can be grouped into two categories—those that produce flowers from old wood (branches that form the previous season), and those that will flower from new wood (branches that form the same year). Easy, right? Not so easy if you’re not a horticulturist. So we’ll simplify things a little. Fortunately, nearly all of the hydrangeas that produce white or whitish flowers fall into the new wood category, and those that are pink-to-red or purple-to-blue (depending on how acidic or lime-based your soil is) flower on old wood. Not to confuse the issue, but the hot new variety on the market, ‘Endless Summer’, blooms on both old and new wood and comes in both white and pink. We’ll lean towards the ‘New wood’ category on that one.
New Wood (white flowers)
You can cut them down to the ground each spring and they’ll give you great flowers the same year. If they happen to grow like a tree, then cutting them back hard without losing their tree-like characteristics will work just fine.
Old Wood (pink-red to purple-blue flowers)
Thin them out in early spring by removing the obviously dead stalks. You can reduce their overall height if desired by cutting off the top 12” or so of the remaining stalks, making sure some live buds remain along the sides of the stalks. Note: after a severe winter, all buds might be killed, despite your best efforts. In this case, you won’t see any flowers at all that growing season.
Typical Plant Care Instructions
Rhododendron and Azaleas – Shape as desired soon after flowering, but not later than mid-July since next year’s flower buds begin forming at this time. An acidic fertilizer is preferred. Tiny white stipple marks on leaves indicates feeding by harmful lacebug insects on undersides. Use an insecticide and spray as per directions on label.
Most flowering shrubs – No special care. Trim lightly after flowering. If plants become too tall over the years, remove 1/4 to ¸ total plant height in early spring before leaves emerge.
Most hedge shrubs – When new growth elongates to 6-10″, cut growth in half to promote bushiness. Continue procedure until desired height and width is reached, then trim closely as needed.
Most trees, especially Cherries and Plums – No special care if a shrub. Trim lightly any time as desired. Remove “suckers” (vigorous young shoots growing vertically usually from ground level but also from main branches) as they appear. Periodically cut out branches that rub against others. Check for presence of scale insects on branches yearly (white fluffy egg masses and/or 1/8″ tan shields covering adults). Call spray company for a dormant oil application.
Pines – To keep compact, shear ‘candles’ (light green new growth spikes) with hedge shears or clippers when candles stop elongating and before needles on their sides reach 1/2″ in length. (Generally, the last week in May). Timing is critical. Cut off 2/3 – 3/4 of total length. Look for black inchworms devouring older needles between May 1st and May 25th . Worms can eat entire plant in one week if left undetected. Spray with an over-the-counter pesticide.
Re-blooming perennials – No special care. Shearing off spent flowers after initial wave of flowering fades will promote second wave. Otherwise, will flower sporadically till frost. See below for division.
Many perennials – No special care. Divide and thin out periodically (every 3-4 years) if clumps become too large, unmanageable, or have significant dead portions (especially in the centers).
Most ornamental grasses – Cut down to 4″ in early winter or before new growth appears in spring (early April). Can be divided into sections as large as desired with a spade in early spring after the clump greens up. Discard any obviously dead portions.
We have just replaced one or more perennials, shrubs and/or trees in your landscape. Where possible, we have marked your replacements with a colored ribbon.
Your new plants require special attention for at least 4 weeks after planting, until the root system gets a chance to grow out into the surrounding soil. Until then, THE ROOT BALL WILL DRY OUT WELL BEFORE THE SURROUNDING SOIL DOES. Thus we strongly recommend that all replacements be watered BY HAND until established. PLEASE DO NOT RELY ON YOUR SPRINKLER SYSTEM TO DO THE JOB. IT WILL NOT GIVE YOUR NEW PLANT ENOUGH WATER WHERE IT NEEDS IT – IN THE ROOT BALL.
Please DO NOT adjust your sprinkler system to an every-day schedule simply to water a few new plants or a small patch of new sod. You might damage your established sod and shrubs by over-watering them, and the sprinkler heads may not actually provide enough water to saturate the newly installed plants sufficiently.
Following the watering guidelines below will help integrate your replacements quickly into the landscape:
A. Small Shrubs and perennials – by hand with hose and/or bucket
1. First 2 weeks – Water every other day for shrubs and perennials in full sun, every 2-4 days if in shade. Under extremely hot or windy conditions, you may need to water every day. Treat them like house plants and aim the hose directly into the root ball.
2. Next 2 weeks – Cut down to once every 3-4 days.
3. After 4 weeks – Your new shrubs should be somewhat established. Continue to water every 2 weeks by hand as a supplement to your sprinkler system right up until the end of December and throughout the following spring while the plants have leaves.
B. Trees and Large Shrubs – by hand with hose or bucket
1. First 2 weeks – Water by placing the hose directly on the root ball, then turning on the faucet so that the water comes out in a slow trickle. Let it trickle for ¸ – 1 hour. The larger the tree, the more time needed. Repeat every 3-4 days.
2. Next 4 weeks – Water once a week as above.
3. After 6 weeks – Water occasionally as above during extended periods of no rainfall (or about once every 2-3 weeks) right up until the end of December and throughout the following spring while the plants have leaves.
Your new trees, shrubs, and/or perennials require special attention for at least one month after planting, until the root systems get a chance to grow out into the surrounding soil. A little vigilance in ensuring that each plant receives its full allotment of water during this time is the single most important factor in determining the future success of your plants. Keep in mind that the root balls of your new plants will dry out just like a houseplant even though the surrounding soil appears wet. The best way to check the roots is to pull away the mulch from the stem of the plant and use your finger to scrape down an inch or two directly into the rootball to feel for dryness.
Sprinkler systems, even the best ones, will water some areas better than others. After your landscape has had time for the plant roots to spread out and intermingle (at least 6 weeks after planting), this unevenness in sprinkler coverage is not a major problem. But when the plants have just been installed, some plants may not receive enough water from the sprinklers to survive the critical first few weeks. For this reason it is imperative that you make frequent (daily to every second day) inspections of your landscape so you can spot plants that may be dry, and water them by hand to give them the opportunity to grow roots into areas that get more water.
Following the guidelines below as a supplement to your sprinkler system will help integrate your plants quickly into the landscape:
A. Shrubs and Perennials – by hand with hose and/or bucket
1. First week – Water every 2 days for shrubs and perennials in full sun, every 3-4 days if in shade. Under extremely hot or windy conditions in full sun, you may need to water every day. Treat them like house plants and aim the hose directly into the root ball. Make mental notes of areas that seem to need extra attention.
2. Next two weeks – Water your extra-attention areas as above. For the areas that are not a problem, water once a week just to be sure.
3. After 3 weeks – Your new shrubs should be somewhat established. Continue to water your extra-attention plants once a week by hand until the end of the season as a supplement to your sprinkler system.
B. Trees and Large Shrubs – by hand with hose or bucket
1. First two weeks – Water by placing the hose directly on the root ball, then turning on the faucet so that the water comes out in a slow trickle. Let it trickle for ¸ -1 hour for each plant. The larger the tree and the more exposed it is to wind and sun, the more time needed. Look for special-attention plants. Repeat every 5-7 days depending on weather and sunlight conditions.
2. Next four weeks – Water twice as above during this period.
3. After six weeks – Water those special-attention plants during extended periods of no rainfall occasionally as above until the end of December.
First month – Watering is the most critical factor for the rapid and healthy development of your lawn. To promote germination, the seed and young grass should not be allowed to dry out for the first three weeks after seeding. The lawn area should be kept moist but not saturated. A daily schedule consisting of a light watering early in the morning, a light misting in the early afternoon, and a second light misting in the later afternoon (especially during hot, dry weather) will help achieve this.
After first month – After the grass greens up and reaches a height of about 3″ (about 30 days), watering should be adjusted to approximately 35 – 45 minutes (rotary heads) every 2 days in Summer (in Spring and Fall every 3-4 days). ONCE THE GRASS HAS BEEN ESTABLISHED, DO NOT WATER EVERY DAY. This can lead to disease problems, drowning of roots, and weak root development. If the lawn is drying out in the summer heat, increase the time per zone rather than the number of watering days per week.
BEST TIME TO WATER – between 1 a.m. and 10 a.m.
WORST TIME TO WATER – between 4 p.m. and 1 p.m. (Fungus will develop and grow when the grass stays wet for more than 6 or 7 hours during the course of the night, so avoid the urge to water your lawn in the early evening.)
First mowing – About 30 days after seeding. TIMING IS CRITICAL. If the lawn gets too long it will fall over and mat down, leading to the development of disease. The lawn should not be watered within 24 hours of the first mowing so that the mower tires and workers’ feet don’t make ruts in the wet soil. Make sure to turn off your sprinkler clock the night before. The mowers should cut off no more than the top 1″ of the grass blades so that the grass will not go into shock. Resume normal watering after mowing.
The establishment of a healthy lawn from seed is a long-term process. Use of the seeded area should be limited as much as possible while the grass is getting established. Depending on the time of the year the seeding is done, it may take up to 12 months to reach the look of a sod lawn. The ideal time for seeding and touching up of seeded lawns is mid-August to mid- October. Avoid use of crabgrass control while the lawn is newly seeded.
Apply a complete fertilizer only after the lawn has been up for at least 30 days. Avoid fertilizers heavy in Nitrogen (the first number of the three that appear on the bag) for this first fertilization. An ideal balance would be in the range of 10-30-15 (as opposed to 25-3-3). After the initial fertilization, follow a May-August-Thanksgiving fertilization schedule (i.e. 3 applications per year). If you are a chemicals minimalist, then use an organic fertilizer and apply on Thanksgiving only, or again in July.
First week – Every day for 15 minutes (mist zones) to 45 minutes (rotary zones) per day for zones in full sun or on slopes, 10 minutes (mist zones) to 30 minutes (rotary zones) for zones in shade half the day or more.
After first week – should now be changed to 20 minutes (mist) to 45 minutes (rotary) per zone every two days (summer), every four days (spring and fall). For low-lying zones that tend to stay wet and zones that are shady most of the day, watering time should not exceed 30 minutes, and preferably these problem-area zones should be shut off and turned on manually only when necessary. WATERING EVERY DAY, REGARDLESS OF TEMPERATURE, CAN LEAD TO DISEASE PROBLEMS AND DROWNING OF ROOTS. If your lawn seems to be drying out in the heat of the summer, increase the time per zone rather than the number of days per week that the system goes on. Lawns will tend to turn light brown in spots during times of drought, but will green up again after the next heavy rain. Watering schedules should be adjusted to accommodate for natural rainfall.
BEST TIME TO WATER – between 1 a.m. and 10 a.m.
WORST TIME TO WATER – between 4 p.m. and 1a.m. ( Fungus will develop and grow when the grass stays wet for more than 6 or 7 hours during the course of the night, so avoid the urge to water your lawn in the early evening.)
First mowing – 7-10 DAYS AFTER LAYING. TIMING IS CRITICAL. If the sod gets too long it will fall over and mat down, leading to the development of disease. The lawn should not be watered 24 hours prior to first mowing so the mower tires and worker’s feet don’t make ruts in the soft, wet sod. Make sure that you turn your clock off the night before the grass is scheduled to be cut. The mowers should cut off no more than the top 1″ of the grass blades so that the grass does not go into shock. Resume watering after mowing.
Second mowing – Ideally, 4 to 5 days after the first mowing. Follow the same instructions as for the first mowing. (Practically, it will be difficult to get your maintenance company to break their weekly schedule.) After this, a regular mowing schedule can be established.
Fall Color Ideas
Fall is not just for mums anymore. Your choices for Autumn and Winter color are far more varied than just a few years ago. Try combining mums with new varieties of Ornamental Kale and Cabbage, Millet (a red-leafed, wheat-like flowering grass), the more compact varieties of Maiden Grass, and Algerian Ivy to really brighten up your pot and bed arrangements.
And once Thanksgiving comes, pop out the spent mums and add a mix of white Birch stems and Red-Stem Dogwood branches for height. Use layers of evergreen boughs like Spruce and Pine as a cover for the soil. If this winter is anything like the last three years, you’ll have color right up through New Year’s Day.
Fall Gardening Tips
Around September 30th: Shut down irrigation clock and run manually only when needed
September 20th through October 10th: Time to plant fall Mums
September 20th through Thanksgiving: Time to plant Ornamental Kale and Cabbage
October 1st through Christmas: Time to plant spring bulbs.
November 15th through December 1st: Time to apply your last lawn fertilization.
November 15th through December 1st: Time to replace spent mums with Holiday color.
November 15th through December 15th: Time to remulch perennial beds.
Thanksgiving through March 15th: Time for winter pruning of all trees and shrubs
Early fall, from early September through late October, is a great time to put plants in the garden. The shorter days and cooler air temperatures reduce the demand for water and keep plants from producing an abundance of new leaves, while the still-warm soil promotes root growth. Thus plants have plenty of time to build a healthy root system and get established before the onset of winter.
Late August through mid-September is also an ideal time to divide and replant those perennials that have become overgrown. Irises, Hostas, Daylilies, Coreopsis, Black-eyed Susan, summer Phlox, and Astilbe are just some of the perennials that can be divided at this time.