GARDENING WITH CONFIDENCE™
THIS MONTH IN THE GARDEN
Mid-Atlantic Region
May Maintenance Guide
INTRO
May brings the end of pollen and summer begins – at least Memorial Day weekend – the official kick off of summer.

CONTAINERS
- Every garden has room for container gardens. Find some fabulous pots and fill them with whatever you fancy. Know the amount of sun you get and when. It matters when you select your plants. Remember they need extra watering and fertilizing.
BULBS
- It’s safe now to plant the Amaryllis from Christmas. It will not likely bloom again this year, but should do so next year. Mine from previous years bloom mid month. Here’s a little Amarylis planting how-to.
- Now that the soils have warmed, plant Caladium bulbs or those potted and already in leaf. They like it warm and can be damaged by a cool weather, not just a frost. They are also big feeders so they will need consistent watering and fertilizer during the growing season.
- Actually, any tender summer bulb such as cannas, dahlias, ginger lilies, and tuberoses can be planted now.
- Oh, the Irises are blooming their little heads off. Recently, I cut some for a friend. She took a whiff and realized for the first time, bearded Irises have a lovely scent. They are nice to bring inside to enjoy the smell. After blooming, cut flower stalks to tidy up the plant.
- Cut the flowers stalks of daffodils. Try to ignore the leaves as they die a natural death.
ANNUALS
- With the frost behind, annuals can be planted with abandonment.
- Visit public gardens to see the variety available for planting in our area. The JC Raulston Arboretum is an All-American Selection (AAS) display garden exhibiting the most recent selection winners.
- Direct sow zinnia seed at intervals to have cut flowers through frost.
PERENNIALS
- May is not the ideal time for planting perennials, but they are oh, so available. Plan to plant, but pamper. They will require extra watering to help get established.
- English Ivy is leafing out. English ivy sure seemed like a good idea at the time it was introduced to the USA, but this non-native is very invasive.
- Seeing the Chinese wisteria escaped in the wild brings a feeling of wonder. Yes, the color and flowers cascading down from the trees is beautiful, but they ain’t supposed to be there. Think twice about planting one. Instead, the American wisteria, ‘Amethyst Falls’ blooming a little later, is a good choice.
TREES AND SHRUBS
- May is Southern Magnolia’s bloom time. They give so much and we need to do so little for them in return. I like to pluck a Magnolia bloom and float it in a bowl of water near where I read or enjoy the
garden at the end of the day. It last but a day, but what a day it is.
- The Endless Summer Hydrangea is the first Hydrangea to bloom on old and new growth with the ability to rebloom all summer long. I planted my Endless Summer in 2005 and I find the reblooming ability to be weak. Perhaps it will improve with age. To encourage reblooming, cut the blooms for drying or to put in vases for a fresh arrangement. This will also encourage the plant to set new buds.
- Prune rhododendron and azaleas right after flowering.
ROSES
- Roses are in full swing right now. Let your roses flush out and take shorter pruning tactics in May so they grow taller. This is usually good advice for the first couple of cuttings. Then you can prune at will remembering to cut at an angle at the next 5 leaflets. Remember, Roses are heavy feeders – both food and water. I fertilize once a month and give each rose about 5 gallons of water each a week or about an inch a week. Water at the base of the plant and in the morning to help discourage black spot.
HERBS
- Plant an herb garden! If not for you, then for your garden friends. The Tiger Swallowtail butterfly larvae love parsley and fennel. Let those ‘green worms’ eat it all. Or plant enough to spare. If you don’t want them, call me at 781-0199 and I will rescue them to my gardens.
- May, in my garden, is Lavender peak bloom time. Each May, I’m
reminded of why I grow Lavender. It can look ratty many month of the year. After it flowers, cut back and shape.
FERTILIZER
- To encourage flowering, a fertilizer low in nitrogen and high in phosphorus is best. The fertilizer’s 3 main ingredients are N-P-K with N for Nitrogen, P for Phosphorus and K for Potassium. 10-10-10 means there is an equal proportion of each N-P-K. Hydrangeas like a low N and a high P, thus a combination of 10-40-10 would be ideal. My general rule of thumb to remember what the numbers mean is to start with the first number and apply from the top of the plant to the bottom. As such, N – is for the green; P – is for the bloom; and K- is for the root.
- To refresh your understanding of pH, pH refers to the acidity of the soil and is measured by the number of Hydrogen ions present in the soil. pH is a logarithmic scale based on the power of ten. As such, pH of 6.0 is 10 times more acidic than pH of 7.0! Thus, even a little change in pH can make a big difference. A pH of 7 is neutral, less than 7 is acid, greater than 7 is alkaline. Most plants like a pH between 6.5 and 7. All hydrangeas like it more acid than most plants.
MULCH
- Keep your gardens cool, less thirsty, and reduce the amount of weeds, top dress your garden beds of mulch. I can write volumes on the benefits of mulch. I am really mulch crazy. I believe in the power of mulch.
- For my Roses, I use mini-nuggets, but for my perennial gardens, I used composted leaf mulch.
- Picking up a load reminds me of how important it is to make sure your yard waste is separated from your trash. This is not only good stuff once it is composted, but the conservation practice is in all our best interest! Confessions of a Stainable Gardener – Part 3 Mulch
WEEDS
- Spring is prime growing time for weeds too. The best advice is to stay on top of them with a weekly weeding event.
WATER
- Now that we are past the last frost, irrigation systems are firing up. My appeal to you is not to water if you don’t have to. Most people OVER water, not underwater.
- Remember, don’t water because it’s Tuesday or Saturday or any particular day of the week. Water when the top 2 or 3 inches of soil feels dry and then only if the plant looks thirsty.
WILDLIFE
- Keep your wildlife coming back for more. Fill your feeders, replenish the water in the birdbaths, don’t spray pesticides.
FOR YOUR CONTINUAL EDUCATION
- For Your Continual Gardening Education, look for garden tours going on this spring, summer, and fall. There is also a fantastic winter garden tour at the JC Raulston Arboretum in February each year. Garden tours are a great way to see how others use certain plants and garden accents, and they can give you endless ideas. If you are new to this area, this is a must for practical purposes and pure pleasure. Garden owners opening their garden are putting their hearts on their sleeve to share with you their passion and giving back to the gardening community. Support our local gardeners who are giving us so much. During the Garden Conservancy’s Open Days tours also benefiting the JC Raulston Arboretum, you may be surprised to know all the notable gardeners and garden writers who come. Even some the most veteran gardeners attend, those who are smart enough to know there is always someone new to learn from and new pleasures to be found.

Guide and photos by Helen Yoest
Gardening With Confidence












success, even if it may be short lived. I use to, but don’t anymore. I find it is even risky planting plants on the zone’s edge. Ideally, I like to wrap a zone around a plant, putting me into choosing plants for zone 7a, but not always. This year, I will be replacing a Clematis armandii, zoned for our 7b gardens. But, alas, we had a particularly hard winter.
I can amend my soil. I have amended all my garden beds, one planting hole at a time. Adding composted leaf mulch or other organic matter to the hole and blending it with the clay with some added insurance of a permanent clay buster such as PermiTil, I can make my sticky clay soil friable. In any garden soil type, you cannot go wrong adding more organic matter. Then top dress the garden beds with a lush, thick layer of mulch each year to moderate the soil temperature, suppress weeds, retain water and generally tiding up the garden. By doing so, you’ll have a happy garden.
watering zones. When I garden shop, the plants watering needs are a high priority for me. But because my garden is designed in zones, it narrows down where I will plant it in the garden. This also makes my garden purchases easy. I wont waste money on a thirsty plant requiring shade if the only area in my Oasis zone is sun. Also, it allows me to have a mental map of my garden with me at all times. I do not want to spend any more time than I have to on watering. The thought of dragging a hose around, past 10 drought tolerant plants to reach one thirsty plant is not part of my makeup. I’m way smarter than that.


























As I sit here writing this, I see several more. The birds, bees and butterflies are abound.

