Gardening Month by Month – August

In Addition:

• Deadhead roses, dahlias, and any summer ‘perennials’ that still have additional buds. Regularly do the same for annual bedding plants to prevent them from setting seed. This practice encourages more vigorous flowering, allowing them to continue blooming into the autumn.
• Take your greenhouse plants outside and hose them down to assist with pest management.
• Plant autumn bulbs like Crocus, Daffodils, and Nerines in both pots and garden borders.
• As summer progresses, roses also become increasingly susceptible to black spot, which causes leaves to yellow and develop dark spots, leading to leaf drop. It’s important to remove the affected leaves and dispose of them properly (avoid composting) and to apply a fungicide spray to manage the issue.
• While deadheading helps you manage your garden and promote new blooms, leaving some seed heads can add visual appeal. Additionally, it provides an opportunity to collect and ‘save seeds’ before they naturally drop.
• Give special attention to container plants this month, as their roots will be tightly packed by this time, requiring increased feeding, watering, and deadheading to maintain their appearance.
• Be decisive with any plants in containers that are clearly beyond saving, particularly those that have dried out significantly. Remove them and replace them with fresh fuchsias, pelargoniums, or autumn pansies in new compost. Consider adding water-retaining gel crystals to help retain moisture.
• To ensure Wisteria blooms annually, regular pruning is crucial. Prune in summer (August) and winter (February) for a beautiful shrub. For helpful tips on how to summer prune Wisteria, check out this Wisteria pruning video.
• For lawns planted on thin or a poor soil base, consider using a high phosphate fertiliser. This will help strengthen the roots for winter, instead of promoting excessive top growth that may be vulnerable to cold conditions and weaken the grass.
• You can sow directly in the ground hardy annuals, like poppies, sunflowers and dill in bright, sunny locations to ensure vibrant colours in your garden by early summer next year.
• Prune/Trim lavender after it has finished blooming to keep it compact and bushy, but be careful not to cut into the old wood.
• Take geranium cuttings now, as they are actively growing and will root quickly, providing you with plants for your windowsill throughout the winter.
• Even though weeds grow more slowly than in the spring, it’s a good idea to keep hoeing the soil to suppress them. This should be done in warm, dry conditions to help any remaining weed seedlings on the surface dehydrate and die.
• Plant foxgloves, sweet rocket, sweet williams, and other perennials now to allow their roots to establish and promote significant growth before autumn.
• Avoid removing the flowerheads/inflorescence of ornamental grasses, as they add visual interest during the winter months.

In Addition:

• Try improving soils with green manures. Green manures are quick-growing plants such as Phacelia and Mustard that are planted to cover bare soil. Commonly used in vegetable gardens, their leaves help suppress weeds while their roots protect against soil erosion. When incorporated into the soil while still green, they enrich the soil with valuable nutrients and enhance its structure.
• After they have produced fruit, the canes of summer-fruiting raspberries should be cut back to the ground.
• Lots of your crops can be harvested in August if you have them. These include beetroot, carrots, cucumbers, courgettes, runner beans, globe artichokes, and second early potatoes, with maincrops potentially ready by the end of the month. Additionally, you can harvest onions and shallots; ensure to let them dry in a sunny location before storing them.
• You can still sow a variety of crops in August for harvests extending into autumn and beyond. These include lettuce (which should be kept out of direct sunlight though), rocket, spring onions, radishes, mustard leaf and lamb’s lettuce and winter salads.
• Keep a close eye on your tomatoes and potatoes for signs of blight, which will initially appear on the leaves. This can often be prevented using Bordeaux mixture (a fungicide and bactericide made from copper sulfate, calcium hydroxide (lime), and water). Additionally, you can protect potatoes by earthing up the tubers.
• Another issue to monitor is blossom end rot on your tomatoes, which initially appears as a brown or black spot on the fruit that enlarges and becomes sunken. To prevent blossom end rot, ensure frequent watering, as this condition is often caused by a lack of calcium in the plants.
• Keep an eye out for seed potatoes to grow new potatoes for Christmas. These prepared tubers can be planted now in a frost-free greenhouse or in containers that can be moved indoors when it gets cold. They will take approximately 12 weeks from planting to harvest.
• Lift and pot up/transplant strawberry runners (stolons) to a new location.
• Inspect your fruit trees for brown rot and promptly remove any affected fruit to help prevent its spread.
• Summer prune, trained apples and pears, particularly those shaped as cordons, espaliers, fans, pyramids, and stepovers. This practice helps sunlight reach the fruit for better ripening and promotes good cropping for the following year.

In Addition:

• Oxygenating plants such as Elodea and Hornwort tend to grow vigorously during the summer and will require thinning. Limit the clump to no more than one-third of the pond’s surface area by removing the older, darker stems while keeping the fresh green ones. Place the removed foliage at the pond’s edge to allow any pond insect life to crawl back in if needed, and then compost the rest.
• Continue to top up the water in ponds and water features as needed. To aerate the water during hot, humid weather, leave fountains running overnight.
• Waterfalls/water features can become clogged with algae, leaves, and debris, so remove these obstructions by hand or with a stiff brush to ensure the water can flow freely.
• Perform a nitrate test to check the levels in your pond. The more frequently you change the water, the lower the nitrate levels should become. Regular water changes also help buffer pH and support fish growth. Always remember to use a dechlorinator.
• During the summer season, there are many herons present, and they become bolder as the summer progresses, often appearing during the day and approaching residential areas. To effectively safeguard your fish, it’s essential to use a securely fitted cover net. Just consider elevating the net above the water’s surface and or reducing the water level, as this can help prevent determined herons from reaching through the net and harming the fish.
• Some fish may develop ulcers during the summer months, so it’s important to change the water as necessary, clean the filter, and ensure the UV system is functioning correctly. If necessary, use anti-ulcer medication to address the issue, you may even need to reduce the fish population if overcrowding is a problem. Ulcers are bacterial infections that thrive in stressed fish and poor water conditions.

• August as in July is an ideal time to continue to inspect fences, trellises, and garden furniture for signs of wear and tear caused by the summer sun and rain. Carrying out repairs as quickly as possible, to prevent further deterioration and help extend their life.
• Regular maintenance ensures your greenhouse provides optimal growing conditions regularly clean panes to maximise light penetration. Also, check for broken or missing panes and replace them promptly. Inspect the ‘frame’ for damage and repair as needed.
• Ensure greenhouse ventilation is working efficiently to prevent overheating. Clean gutters and downpipes to avoid waterlogging.
• Check patios and paths for weeds pushing through cracks. Remove these promptly to prevent damage.
• August is also a great time to clean and maintain your garden tools. After a busy summer, ensure they are free from dirt and rust. Sharpen blades and check for any repairs before the autumn gardening season begins. Proper maintenance will extend the life of your tools and improve their performance.