An overly soggy garden that dries out over a few days can be revived without too much fuss, but a flooded garden needs a deeper clean-up and a few more steps to keep you safe and get your garden back to health. If plants are left to stand in water for more than a few days, they can die from lack of oxygen supply to their roots and if they do manage to survive then fungal diseases that develop in these conditions may still be a major challenge.
When flood occurs, toxic compounds can wash into your garden such as chemicals, petroleum products and raw sewage along with pathogens and unwanted weeds. Then there is silt. This is a sediment of dust sized partials that move easily in water and when the water recedes, the silt will compact and lead to increased acidity and oxygen starvation in soil. When this silt and mud is left on plants it will also stop the process of photosynthesis. Once the sun returns its gaze upon our gardens, it’s time to get into rescue mode, but not so fast! There is a right way and more importantly, a safe way to save our plants.
First Steps to Recovery
As always, safety first and if your garden was flooded then you need to wear waterproof gloves and boots and a mask is also advisable. This is to reduce the risk of you becoming infected with pathogens. If your garden flooded then you need to wash away any left behind silt and mud from plants, paths, structures, and the surface of the garden as soon as possible. Silt will harden as it dries and be difficult to remove. Get rid of all debris that has fallen or swept into your garden as soon as possible as rotting plant materials will contribute to the spread of disease and fungal activity as well as invite pests in. Let the garden dry out, don’t start planting just yet and do not eat any raw leafy greens, soft fruits, or berries as these will more than likely have absorbed dangerous levels of contaminates. Rule of thumb is to not eat produce for a month, to wash with soapy water and cook before consuming. If you suspect that your garden has been contaminated with raw sewage, then you should remove and destroy annuals and not consume from longer living plants until the following year.
After washing, dig in any remaining silt and turn over soil well to help aerate the garden beds. Your soil will need to be treated with fungicide as well to hold back outbreaks. All that water would have also washed away nutrients and even broken down your soil structure. This needs to be repaired quickly so that your existing plants have a better chance at survival as well. Do a soil test to determine what may be needed to improve your soil and add organic matter, fertilisers, and composts to replace lost nutrients. If you can get hold of a bunch of seaweed, then mulching with this will help increase fertility of soil, break down any remaining silt and encourage the return of worms but any organic mulch will help.
You need to be tough and face the fact that some of your plants may not recover but you can help by using fungicides and pest control methods. Use seaweed solutions liberally as these promote strong root growth and are an amazing health tonic for stressed plants. Be ready for competing weeds to start showing up as they move in more easily with silt and remove as soon as you see them. If a plant seems beyond rescue, be strong and remove it as it may infect other healthier plants in your garden.
Flooded lawn areas can be saved if the remaining silt is less than about 2cm deep. Try and wash off as much as possible and go over the surface with steel rake to break up the silt surface. Hose on a seaweed solution to encourage root growth. For deep silt, you may need to start again but the trick is to get rid of the silt and to get air into the soil below.
When to Plant Again
General advice it to wait at least 60 days after flooding until you plant again. For those gardens that experienced heavy rainfall without actual flooding, test the readiness by rolling a ball of soil in your hand. If it will easily crumble when pushed with a finger and no water can be seen oozing out, then you are right to plant. If you need to wait, there is nothing stopping you planting your seeds in seed pots and trays while your garden recovers. By the time the seedlings are ready, your garden will have had time to rest, repair and rejuvenate.
I’m not too sure there is such a thing, but here are a few ways that may help reduce the risk of flood and help water drain more easily from your garden. Create a slope to your garden, even 2 degrees can be enough, so that water runs off more easily and make sure it slopes away from buildings. The installation of drains and even the clever French Drain will help immensely. These are also known as ditch drains, French ditch, sub-surface drains and land drains and they not only help save your garden but will pull water away from the foundation of your home as well. They work by collecting overflowing water and filtering it through gravel or rocks. Selection of plants is always important so considering planting more natives as these will generally be more adaptable to conditions and to recovery as well as helping stop possible soil erosion. To direct water away from your house and to store for later use, install a water tank and consider rain barrels under your down pipes. Collected water in these can be used for the garden later.
YOU AND YOUR GARDEN
Soil to Plate with Youth Connections and SWAMP
Sustainable Wetlands Agricultural Makers Project (SWAMP) at the Central Coast Wetlands is facilitating an amazing project with Youth Connections of Tuggerah. Created with the support of Central Coast Council and delivered by the enthusiastic volunteers of SWAMP, it is a grass roots pilot program aiming to deliver a nature, gardening, cultural and educational program for the young clients of Youth Connections. In the spirit of ‘soil to plate’ the project will see the creation of a ‘pizza garden’ and then the cooking of pizzas to share with family and friends. In the first week Youth Connections participants travelled to Narara Valley Nursery to begin the preparation and decision making around what will be needed to create the pizza garden. The youth engaged with decisions about which soil, what seeds or seedlings they might like in their garden, as well as the smells and sounds of a bustling nursery with a wide variety of plants. In the following weeks an above ground garden was established at the SWAMP community garden site by the group for the selection of herbs and vegetables that will eventually find their way into on to the pizzas. Other activities included kitchen apron making and a joyful visit to Grace Springs Farm in Kulnura which enabled all to experience agriculture on a larger scale.
Thank you to Syl Marie Photography.
GARDENING GUIDE FOR COAST GARDENERS THIS WEEK
With all this rain, again hold off on planting anything directly in the garden but you can plant out seeds in sheltered spots. You can plant the following now: Culinary herbs, beetroot, broccoli, brussels sprouts, cabbages, carrot, cauliflower, chicory, cress, endive, kohlrabi, leek, lettuce, mustard, onions, parsnip, peas, salsify, shallots, spring onions, silverbeet, swede, spinach, turnips, ageratum, alyssum, calendula, candytuft, carnation, columbine, cornflower, delphinium, dianthus, everlasting daisy, forget-me-not, foxglove, godetia, gypsophila, hollyhock, larkspur, nigella, pansy, polyanthus, poppy, primula, snapdragon, statice, stock, sweet pea, wallflower
Next Week: Start Seed Saving
HAVE YOU GOT A GARDEN OR GARDENING TOPIC TO SHARE?
Down in the Garden is looking for Central Coast gardeners who would like to share their garden with us. We are particularly looking for: Evergreens, Tulips, Spring Bulbs, Water Feature Gardens, School/Children Gardeners, Commercial Kitchen Gardens, Medicinal Plant Gardeners, and Community Gardens but all gardens and gardeners are welcome contact: [email protected]
Cheralyn Darcey is a gardening author, community garden coordinator and along with Pete Little, hosts ‘At Home with The Gardening Gang’ 8 - 10am live every Saturday on CoastFM963. She is also co-host of @MostlyAboutPlants a weekly botanical history & gardening podcast with Victoria White. Archived articles can be found on Cheralyn’s Blog: www.florasphere.com
Send your gardening questions, events, and news to: [email protected]