August in the Garden

August is usually the peak of hot, dry weather. Time spent in the garden is often focused on watering, training, weeding, mulching, harvesting and watching out for pests and diseases. The frenzy of early summer is over and the hot summer days entice us to spend time sitting and enjoying and maintaining all the results of our labors.

If you’re heading out for a vacation this month, remember to arrange a sitter for you garden to water, weed, harvest and tend your plants while you’re gone! If you can’t get someone to come water your indoor plants while you’re gone, a put them outside in a cool, shady corner of the garden, or, even better, dig a hole and put the potted plant in the ground, this way they will not dry out as quickly as if they were fully exposed to the sun and wind.

Make sure to protect your skin and eyes from the sun’s rays during their peak hours and hydrate! It’s not good for you or the plants to be doing garden work during the hottest days or the hottest parts of the day. Use those peak hours and days of extreme heat to do some more important work: like enjoying the fruits of your garden, sitting under the shade of a lovely tree, sipping a cold beverage, and catching up on your garden journal!

Design

Use your garden journal to record details about your new plantings, the weather, pest problems, plant care, new plants on your wish list. Look back at your spring garden designs and make changes as needed, update any plants that got planted in different spaces than were planned, surprise additions and plants that did not make it or don’t look like they will. This is a great time to do some plant research on your plant wish list and design for fall planting, note the plant’s name, variety, bloom time, soil, sun, pH and water preferences, and other features that caught your attention. What wildlife to they attract or feed or provide habitat for?

Take time to appreciate the beauty you’ve helped create in the garden and to notice who else has come to visit and enjoy it, what birds and insects and mammals? What volunteers have popped up in the soil? Now is a great time to learn more about botanical terms and plant identification and practice plant identification. If you are wanting some places to start, I would recommend Peterson’s Field Guides (on trees, birds, plants, etc) and for edibles in particular Sam Thayer’s field guide, and the identification phone app iNaturalist, which has been shown to be the most reliable at identification. Use it as a starting point however and follow up with doing your own research and paper field guides like these to get a thorough identification. If you really want to get to know wild plants like this, consider starting a plant journal. Get to know wild plants where they appear, note what conditions you find them in, who they grow around, what wildlife visits. Take time to sit with them and get to know them, for me the best way is through drawing them.

Back in the garden, think about (and order if you haven’t) any fall or spring flowering bulbs you would like to put in. Find a location that tolerates their early spring leaf growth but wont be disturbed by deep cultivation over the growing season. Autumn crocus in particular mixes well with ground covers and low-growing perennials that do not need dividing (plants with taproots, woody crowns and sub-shrubs, plants with brittle or fragile roots, or with thick woody roots.

Consider what perennials you have that may need to be divided this fall, or that could be, and what gaps you have in the garden, or who you could give plant divisions too. Often these are spring to early summer flowering plants. Look back at your updated spring garden design and think about where you could plug these divisions into your garden. Dividing in the fall can be easier on you and the plants because you are heading into cooler and wetter weather (meaning less watering for you!), there are generally fewer garden tasks in the fall, the plants are easier to see and find compared to spring. Where I am in in Lansing, late August up until late September is when I divide and plant in the fall. Just make sure to water them thoroughly after your divide them and support them during the fall with water when there isn’t rain to help their roots get established.

Additionally, keep an eye out for plants showing distress like brown leaf edges or scorching, these may need shadier or wetter conditions that they are getting, consider where you could move plants to a more suitable location in the future.

In the Garden

Bulbs

Finish digging and dividing irises this month, cut leaves in a fan shape back to 6 inches, and when digging rhizomes make sure to check for borers and remove old and damaged rhizomes. Plant healthy rhizomes back to back with growing point out or 5 inches apart, with rhizomes just below the soil surface with leaves and buds facing upwards.

Leave foliage on tender and summer bulbs as long as possible, dig bulbs out only after foliage has yellowed and died naturally. They need this time to store energy in the bulbs for next year! Late August you can start planting spring flowering bulbs, especially daffodils.

Pruning and Deadheading

Prune rambling roses after flowering and trim lavender plants once the flowers have faded gto encourage side shoots to grow. This is your last chance to finish summer-pruning apples and pears as well as other trained fruit trees. Summer prune those gooseberry and red currant plants, and to complete summer pruning of wisteria and hedges.

Deadhead annuals and perennials to keep the blooms popping and prevent reseeding (I’m looking at you valerian and catnip). You can always leave a few past blooms to collect seeds from. Seed saving can be a very rewarding part of gardening, but you will need to be vigilant and keep checking seed pods or heads that may not look ready, if you miss their window you’ll miss getting seeds and they spread themselves around the garden (and/or get eaten by birds), both of which are not necessarily a bad thing either though. Seed heads are usually ripe when they turn brown, then cut them off and store them in a brown paper bag to be cleaned and stored later on. Spread these out on a sheet of paper and leave them to dry, then separate the chaff from the seeds and store them in labeled paper envelopes (make them yourself with recycled paper) or class jars.

Summer pruning some annuals and perennials that bloom in late spring and early summer will encourage new growth, tidy up the garden and sometimes encourage reblooming, like yarrow, catmint, lavender, anise hyssop, perennial geraniums, and lady’s mantle. Keep in mind timing however, you’ll want to prune on cooler days or in the cool morning or evening, preferably on calm days with little wind as well, otherwise your plant will lose a lot more water and be more stressed. If you are in a period of drought, like we have been, only trim if you are going to help the plant recover with watering and perhaps a compost application.

Make sure to cut back perennials that have collapsed or spread over outside their beds or onto other plants, you don’t want them to smother taller plants! Plants that have flopped, especially native plants, may have too rich a soil for their needs. In the future give them only leaf mulch compost (aka leaf mould) and a trim earlier in the year to reduce their and stem height. See how to make your own leaf mould here, I would caution against using leaves from juglone-producing species however like black walnut, hickories, butternut, and pecans.

Annual Vegetables and Herbs

Remove done vegetables and seed cool season crops or replace with starts. Keep seeding short season cool crops that can be harvested before the first killing frost, radishes, greens and scallions are great for this time of year, but there is still time for beets, carrots, chard, Chinese cabbage, cucumber, kohlrabi, bush beans, cucumber, cilantro, parsley peas and turnips in the southern parts of the state. You can also pot up existing herb plants to bring them inside in late fall for fall and winter use. Make sure to give your soil a fresh layer of compost before you do! August is generally potato and onion harvest time here. Harvest potatoes as the the tops die, carefully dig them up, and store in cool, dark location. If they are storage potatoes, cure them in a sheltered area with good ventilation first before putting them in storage. Dig onions when the tops fall over and begin to dry, cure the bulbs you plan to store, usually 1-2 weeks in a cool, dry location with good ventilation. This is also the time to harvest and dry a lot of our herbs to store.

Lawns, cover crops and green mulch

Dormant lawns should be left dormant until the drought conditions of summer pass, try to minimize traffic and mowing during this time. It’s better to leave lawn a little longer before the summer dry period starts, they stay greener and cool the area around them better and longer than a short clipped lawn. As the weather cools and rain become more reliable again, it becomes a good time to seed lawns, fall cover crops or green mulch areas. The soil is warm so seeds germinate quickly, but the temperatures are cooling and perfect for growing grass. It’s also the time to divide perennials and plant new perennials, including vines and groundcovers.

Fall Planting

Late summer and early fall are also excellent times to plant shrubs and trees, and many stores have sales on plants at this time of the year. But keep in mind, drought stressed and poorly maintained trees and shrubs are not worth the bargain, they can be slow to establish and may never full develop. Consider buying bare root trees and shrubs and planting them in late fall as well, it is one of the least labor-intensive methods and in some ways it’s easier on the plant to be moved when it has entered dormancy. Check out Fruitful Landscapes, one of our local nurseries here in Lansing that offers perennial and medicinal plants and bare root plants for sale! When planting fall shrubs, avoid late-season pruning that can stimulate late-season growth, only prune broken, dead or diseased plants. Save major pruning for winter dormancy.

Divide and transplant spring flowering bulbs (hope you marked their spots!) and perennial flowers and herbs that flower in spring-early summer. Make sure to water these well if there isn’t sufficient rain for the first several weeks after transplanting. I personally prefer fall planting over spring planting for perennials, with fall rains, winter snow, and spring rains I find I don’t have to water these plants as much over the plant’s first year and they tend to establish better. And it gives me more time to focus on annual plants in the spring!

Watering, Weeding, etc

Continue watering spring-planted perennials, ideally 1″ a week in 1-2 longer watering sessions (1 for clay soils, 2 for sandy soils) to encourage roots to grow deeper rather than outward at shallow soil levels. Keep an eye on perennials planted last year and water them as they show signs of distress, particularly shrubs and trees that haven’t had enough time to develop deep roots. Gardens that are mulched or in shady areas need less frequent watering. Go by touch, use a finger to test the top few inches of the soil and water when the soil starts to dry. Water early in the morning to reduce the risk of disease and water loss to evaporation, or late evening also reduces water loss to evaporation. Check container and raised bed plantings more often, they dry out much faster.

If you are someone who applies fertilizer or adds compost more often to your perennials, August is a good time to reduce applications to allow perennials, shrubs and trees plenty of time to harden off before the cold weather.

It’s not too late to mulch in the garden! A 2-3 inch layer of organic matter can help conserve moisture and suppress weeds. For native plants a mulch of leaves, straw or grass is recommended over wood, leaves being most recommended. Weed prior to mulching and mulch before you water to help prevent weed seed germination. Avoid piling up the mulch around the crowns of plants which can encourage crown rot. The word offending weeds to prioritize getting are bindweed, poison ivy (careful!) and crabgrass. Other weeds/grasses you can always cut back to the soil surface or near that before they go to seed to prevent their spread, then leave them on the soil surface to dry out in the sun and return their nutrients to the soil. Weeding and mulching are worth the effort, they help reduce nutrient, sun and water competition for the plants you want, keep your garden looking attractive and prevent further headaches and labor later.

Keep an eye out for plants showing distress like brown leaf edges or scorching, these may need shadier conditions that they are getting, consider where you could move plants to a more suitable location in the future, but for now, mulch the soil, water deeply and remove badly scorched leaves.

What Can I Do For You This Fall?

Fall is a great time to contact a garden designer like myself to get help with your garden’s design for the spring, then we have plenty of time for me to take measurements and map the site and get feedback and make changes on the design over the winter. If a specific bed or area is giving you trouble, we can prioritize making some design and planting changes this fall. You can learn more about my design process here.

If you are looking for a garden-sitter this fall while you are out of town (and live locally), I can help with the simple garden maintenance of watering and harvesting (and can donate produce to the Breadbasket Pantry or local Free Stands), but also weeding, planting, mulching and pest and disease control if desired.

If you are looking for help with fall garden tasks and live locally, I can help with that or we can garden together and I can coach you through the season’s tasks as they need doing, and help you spot the opportunities in your garden.

If you are wanting to work on your properties design yourself over the winter, and are looking for a fresh and experienced perspective to help you on your own design journey, I can visit your site and give a consultation.

Contact me to get your fall and spring planting dreams underway!