Gardening Jobs to Do in August

It is mid-summer; for some, this means hot, dry days; for others, it means thunderstorms. For William Shakespeare, it is the season for weddings and fairies in his Midsummer Night’s Dream. I hope you are harvesting this month – and managing the heat. Below is a range of jobs you may have to consider. Please make your lists and work against them. Some must be done weekly, while others will be a one-time task.

Each month’s Jobs-to-Do article has a standard format, and this one is no different:

  • Garden preparation jobs to do.
  • Garden maintenance jobs.
  • Vegetable gardening jobs to do.
  • Fruit garden jobs to do.
  • Indoor and container gardening projects.
  • Ornamental garden jobs to do.
  • A summary of what gardeners should focus on.

Garden Preparation Jobs to Do in August

A person clearing and preparing garden beds for new plantings in August.
August garden preparation jobs: Preparing for a fruitful autumn harvest.

There’s an adage, “You can’t manage what isn’t measured.” Healthy soil matters – even more so than plant health. Soil is the foundation for all your gardening dreams, so knowing its condition is vital – it allows you to understand how to improve its health. Soil tests inform you of the nutrient levels of your soil, the soil pH, and even the soil’s ability to manage those nutrients – the Cation Exchange Capacity (CEC)

Soil samples should be randomly taken from across the yard and submitted to a laboratory. If you want to know your soil’s health, you may want to have the microorganism population reviewed, but that’s a different topic.

Soil pH

The test will tell you if your soil is sour (acidic) or sweet (alkaline) – it even tells you if lime is needed and how much. Iron deficiency is often caused by too alkaline soil – a high pH. The results will indicate the actual pH compared to the target range – based on soil type and what you intend to grow.

Generally, lime is added to increase the pH, and sulfur decreases the pH (increases the acidity). Lime Lifts, and Sulfur Suppresses it. As per the graph below, a pH of 7.00 is considered neutral – most plants prefer a pH range between 5.70 and 6.70.

Lime Recommendation – If the pH is low for the crop you intend to grow, lime will be recommended. The advised rate is in pounds per 1000 square feet. The general rule is that adding lime is safer than adding sulfur – lifting your pH is safer than suppressing it. Remember that adding lime may take six months to move the needle.

Sulfur lowers the pH – apply only the amount recommended by the report, remembering that it takes two to three months to have an effect. A good rule is only to add sulfur if the pH is over 7.5 and plants show micronutrient deficiency symptoms.

Epsom salts (magnesium sulfate) lower the pH and provide magnesium and sulfur, two nutrients often deficient at higher pH. Adding compost is a better course of action, but if you apply Epsom salts, do it at most twice per growing season.

Fertilizer Recommendations

The test’s recommendation will specify the quantity per thousand square feet and the NKP ratios. Let’s review the numbers:

  • N – nitrogen – boosts growth, but not fruit growth necessarily.
  • K – phosphorus – essential for flowers, fruit, and roots
  • P – potassium – also called potash, boosts plant hardiness and flavor.

The test measures the phosphorus and potassium content – nitrogen is too volatile to measure accurately and is often the most limiting nutrient.

  • Promotes green, leafy growth
  • Most commonly deficient
  • It tends to leach into the soil, polluting the surface, and groundwater.
  • Insufficient nitrogen stunts growth and causes leaves to turn yellow – starting with the oldest leaves
  • Too much nitrogen:
    • Burns plants
    • Can increase pest problems
    • Reduces yields – most notable in beans, tomatoes, cucumbers, squash, and peppers
    • Causes thatch in lawns
  • Promotes root growth, flower, fruit, and seed production
  • Held tightly by CEC action in soil, so leaching is rare
  • Causes pollution when soil erodes
  • Needs to be incorporated before planting – at least a month
  • Frequently fertilized soils often have too much phosphorus, which negatively affects nitrogen-fixating microorganisms
  • Insufficient phosphorus causes:
    • Reduced growth
    • Plants dark green – Purple or reddish color to older leaves
  • Note: Phosphorus is not used well in cold or wet soils. Deficiency symptoms in winter are usually due to cold weather rather than a lack of nutrients in the soil
  • Increases drought tolerance and disease resistance and improves winter hardiness
  • Improves flavor in melons and tomatoes
  • Deficiency is hard to observe, though levels are often low

The Essential Nutrient Element – Organic Matter (Compost)

Compost has several benefits that only it can provide – improved soil health, microbe support, tilth improvement, pH buffering, and aggregate formation. It adds some nutrients, but its primary benefit is the soil’s improved water and nutrient-holding capacity – it enhances the efficacy of fertilizers.

Organic Fertilizer Alternatives

  • Nitrogen – blood meal is 12% nitrogen
  • Phosphorus – A bone meal is 10% phosphorus
  • Potassium (Potash) – Greensand is 5% potassium and 1% phosphorus.

Cation Exchange Capacity (CEC)

Your report will provide you with a CEC measurement, the ability of your soil to hold and release water and nutrients to your plants – think of it as your soil’s nutrient magnetism. There’s a whole science to CEC, but the answer is always organic matter – compost. Compost can boost your CEC beyond what any other substance can.

Your annual soil-enriching process should include the following:

  • Soil Test
  • Add compost to your beds – four inches think worked into a depth of 8 to 18-inches
  • Wait a month
  • Add fertilizer and lime as recommended by your soil test
  • Wait at least two weeks before planting
  • Reap the abundant reward of having healthy soil

Garden Maintenance Jobs

A gardener watering plants and inspecting for pests in a well-maintained garden during August.
August garden maintenance jobs: Keeping your garden lush and healthy.

Turf Care Jobs – August

Turf maintenance in August is like July: higher mower settings, taller grass, clippings on the lawn, soaking the lawn once a week, and managing weeds early. August is the last month before winter to boost nitrogen levels (if needed), but it should only be done on wet lawns. Start preparing the ground now if you plan on re-turfing or sowing a new lawn in the fall.

  • As cool-season grasses resume active growth, aerate compacted soil, dethatch lawns, and plan fall duties.
  • To avoid or strengthen thinning lawns, overseed. Do this 45 days before the first forecasted frost in your area.
  • New lawns should be seeded. Late summer and early fall are ideal germination times because of warm soil, lower temperatures, and fall precipitation. Maintain a steady moisture level in newly sown or overseeded regions.

Vegetable Gardening Jobs to Do in August

A person harvesting ripe vegetables and tending to the garden in August.
Vegetable gardening jobs in August: Reaping the rewards of your summer labor.

To prepare for the fall garden, you have two options: compost the residues from your harvested crops or till them under. This is ideal for sowing beans, beets, spinach, and turnips seeds. To ensure better germination, you can refrigerate spinach seeds for a week before planting.

Once you’ve harvested your onions, cure them in a warm, dry place for two weeks before storage. It’s also the perfect opportunity to set out broccoli, cabbage, and cauliflower transplants. You can now plant lettuce and radishes for the fall. Once gourds have an adequate fruit set, you can pinch their growing tips to direct energy into ripening fruits instead of vine production.

Vegetable Planting Guide – August

Use the table below to calculate your planting date. Start seeds indoors if temperatures are too hot. Take note of the minimum soil temperature to guide your planting timing but ensure the crop will be ready for harvest before the expected fall frost date.  

VegetableDays to Harvest
Days to harvest
°F (°C)
Arugula40 to 5040  to  75 (~4  to  24)
Beans, snap/bush50 to 5570  to  80 (~21  to  27)
Beans, snap/pole65 to 7070  to  80 (~21  to  27)
Beets55 to 6050  to  85 (~10  to  30)
Broccoli70 to 8045  to  85 (~7  to  30)
Brussels sprouts90 to 100*40 to 5045  to  85 (~7  to  30)
Cabbage90 to 120*63 to 7545  to  85 (~7  to  30)
Cabbage, Chinese75 to 8545 to 5545  to  85 (~7  to  30)
Carrots75 to 8050  to  85 (~10  to  30)
Cauliflower85 to 9555 to 6545  to  85 (~7  to  30)
Celery120 to 150*40 to 7070  to  75 (~21  to  24)
Chard, Swiss60 to 7032 to 4250  to  85 (~10  to  30)
Chives60 to 7042 to 5645  to  95 (~7  to  35)
Collard greens60 to 10032 to 7270  to  75 (~21  to  24)
Cucumbers56 to 6528 to 3760  to  90 (~16  to  32)
Dill40 to 5560 – 85 (~16 – 30)
Eggplant150 to 155*90 to 9560  to  95 (~16  to  35)
Endives70 to 8545 to 6045  to  85 (~7  to  30)
Fennel, Florence60 to 9060 – 85 (~16 – 30)
Kale40 to 5014 to 2245  to  85 (~7  to  30)
Kohlrabi50 to 6022 to 3245  to  85 (~7  to  30)
Lettuce, head70 to 8545 to 6045  to  85 (~7  to  30)
Lettuce, leaf40 to 5015 to 2545  to  85 (~7  to  30)
Mustard30 to 4045  to  85 (~7  to  30)
Okra60 to 7018 to 2860 to 85 (~16 to 30)
Onions, bulb90 to 12075 to 10545  to  85 (~7  to  30)
Onions, green60 to 7042 to 5645  to  85 (~7  to  30)
Pac Choi/Bok Choy45 to 90*30 to 7550  to  85 (~10  to  30)
Parsley75 days33 days50  to  85 (~10  to  30)
Parsnips100 to 13050  to  85 (~10  to  30)
Peas54 to 6060  to  85 (~16  to  30)
Peppers145 to 150 *75 to 8070  to  95 (~21  to  35)
Radishes20 to 2555  to  85 (~13  to  30)
Rutabaga70 to 8045  to  85 (~7  to  30)
Scallion60 to 7042 to 5645  to  95 (~7  to  30)
Shallots60 to 7042 to 5645  to  95 (~7  to  30)
Spinach50 to 6040  to  75 (~4  to  24)
Squash, summer50 to 6030 to 4060  to  95 (~16  to  35)
Squash, winter70 to 9542 to 6760  to  95 (~16  to  35)
Tomatoes125 to 135*75 to 8560  to  95 (~16  to  35)
Turnips55 to 6045  to  85 (~7  to  30)
Seed to Harvest days and germination temperatures for Fall vegetable and herb crops

* Do not sow seeds in situ (direct to the garden)

Fruit Garden Jobs to Do

Children picking ripe fruits, such as apples and peaches, in a lush fruit garden during August.
August fruit garden jobs: Harvesting the sweetness of homegrown fruits.

Fruit Garden Tasks – August

Consider covering your plants with netting to protect your ripening fruits from birds. Additionally, propping up fruit tree limbs struggling to support their harvest can prevent breakage. It’s essential to spray ripening fruits to prevent brown rot fungus consistently.

Those looking to harvest blackberries without thorns should know that they’re currently ripening. Weed preventers can be applied to strawberry plantations after fertilization to prevent weed growth. Keep an eye out for fall webworm activity at this time of year.

To protect peach trees from borers, spraying peaches and other stone fruits is recommended. Finally, it’s worth noting that red raspberries are currently in season and ripening.

Indoor And Container Gardening Projects

A well-lit indoor space with a variety of containers showcasing thriving plants in August.
Container gardening projects in August: Creating biophilic green spaces.

Keeping an eye out for pests and diseases in your indoor gardens is important to avoid future problems. Jot down any issues in your garden journal for reference. Ensure your indoor plants receive adequate light and adjust watering to suit the surrounding temperature.

Check the soil moisture by tapping the pot – a dull sound means the soil is hydrated, while dry topsoil may require a good soak. Apply fertilizer generously for a final feed before spring. Bonsai growers should do their final pruning and wiring in autumn.

Start browsing seed catalogs for bulbs to plant in the fall and order early for the best selection. If you plan a fall vegetable garden, buy your seeds now and prepare your garden. Start the seedlings indoors this month and ensure you have the necessary supplies.

Check your local garden center and nursery for end-of-season clearance items, such as discounted perennials or garden supplies.

Ornamental Garden Jobs to Do

A beautifully landscaped ornamental garden with blooming flowers and filler plants for gardening jobs to do in August.
Garden jobs to do in August: Nurturing the beauty of your ornamental garden.

Flower Garden Tasks – August

It’s possible that your annual plants may look tired and delicate right now, but with a bit of aggressive trimming and fertilization, a new bloom can be coaxed out of them. Keep spraying your sensitive rose plants to avoid black spot and other fungal infections. Remove any dead flowers from your annual and perennial plants as necessary.

If you have oriental poppies, August is an excellent time to divide them. Avoid adding nitrogen fertilizer to your rose plants at the end of their season. While powdery mildew on lilacs can be unsightly, it typically doesn’t cause much damage and can be controlled with standard rose fungicides.

In August, it’s time to give the final feeding to mums, asters, and other fall-blooming perennials. You can split and replant bloodroot (Sanguinaria), Madonna lilies, and bleeding heart (Dicentra). The bearded iris should be divided now, discarding old center portions and borer-damaged components. When replanting rhizome tops, make sure they are barely above ground level.

If you plan on planting bulbs in the fall, ordering them now is a good idea. Transplanting evergreens directly will also ensure excellent roots before winter. Before transplanting, water both the plant and the planting spot. For the last time this season, shape your hedges by pruning them. If you want colossal dahlia flowers, keep side branches clipped off and regularly water and feed your plants.

It’s best to avoid pruning shrubs during August, September, or October. If you plan to do some fall landscape planting, have a plan. Keep watering your favorite landscaping plants and food garden if the weather is dry.

Using insecticides on bagworms after they have reached their full size is pointless. To have better control, you can prune and burn large bagworms. During dry spells, soak bushes with enough water to saturate the soil up to 8-10 inches deep.

It is recommended to spray black locust trees now to safeguard them against the locust borer. Scotch and Austrian pines may face difficulties due to the Zimmerman pine moth. If you notice pitch tubes near leaf whorls or browning of branch terminals, it is advisable to prune and dispose of the affected areas.

As hummingbirds migrate through gardens, it is a good idea to prepare for the fall by cleaning out cold frames. Keep a watchful eye on plants for spider mite activity, and use a strong stream of water to spray these insects.

What Gardeners Should Focus on in August

A gardener holding a checklist and tending to plants in a thriving garden, representing August gardening tasks.
What gardeners should focus on in August: A guide to late summer gardening.

Creating and maintaining a gardening journal will help you improve your annual gardening routines. As you look back at each month of the previous year, look at what you planned and did and the outcomes of each action. That is one of the shortest routes to becoming proficient at gardening in your context. You face unique challenges in your area – as we all do. If you have not yet done so, start one this summer.


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