Soil is where plants take root. Good soil, means good plants with vibrant flowers, lush foliage and tasty produce. Vigorous plants are also more resistant to pest and disease problems.

Just how good your soil is depends on its natural qualities along with external factors such as climate and weather events including wind, rain, heat, cold.

What’s going on within the soil is also important and affects how plants grow. Good microbial and worm activity in soils can help improve soils and make them better for plant growth. As well, how we treat the soil, what we add to it and how we care for it, also affect how good it is and how well plants grow. Follow our seasonal soil care tips to keep your soil in tip-top condition so your garden and lawn looks good all year round. Read ‘Understanding soils’ for more information on soil.

Winter Seasol Liquid Compost banner - Soil Care for winter gardens

Autumn Soil Care

This season is all about soil rejuvenation and revitalisation after the stresses of a long hot summer. As temperatures start to fall and days get shorter, soil temperature too starts to fall. Autumn is the perfect time for planting as plants don’t come under stress. In early autumn improve soil for planting by following these steps:

  • Weed thoroughly as weeds compete with plants for water and nutrients.
  • Dig the soil over to at least a spade’s depth to help aerate the soil, improving air and water penetration. Work in compost or aged manure.
  • Use a no-dig method (as an alternative to digging) by adding manure, homemade or bought bagged compost such as Seasol Super Compost and mulch to the soil surface and letting soil organisms do the work. Garden soil is full of organisms such as worms, microbes, bacteria and fungi. These critters make nutrients available to plants and bind soil particles together to improve its structure, making it lose and fluffy. The population size and activity of these organisms depends on the existing structure of the soil.
  • If you want an easy to use no-dig option, give the soil a good dose of Seasol Liquid Compost.
  • If the soil is not absorbing water (that is, it is hydrophobic), apply a soil wetter such as Seasol Super Soil Wetter and Conditioner to help water soak deep into soil where it is available to plant roots. Be sure to wash it off the plant’s foliage if it’s applied to planted areas.

Apply mulch to the soil after planting or top up existing garden beds. Organic mulches protect soil from heat and heavy rain and also can add nutrients as they break down. Mulch keeps soil and roots cool or warm depending on climatic conditions. It also can help to prevent water evaporation, retain soil moisture and deter weed germination.

Winter soil care

For many parts of southern and inland Australia winter soil care is all about protecting soil from cold and frost. Winter is the planting time for bare-rooted plants such as fruit trees and shrubs, roses and herbaceous perennials. Follow our easy ‘Autumn soil care’ guide to give you all the tips to prepare soils for planting.

If the soil is being left uncultivated over winter, here’s how to make it more productive in spring and summer:

  • Grow a cover crop including legumes such as peas, beans, mustard plants or subterranean clover (Trifolium subterraneum) to dig in as a soil-improving green manure. Special packaged green manure seeds are available from hardware and garden centres and online suppliers.
  • Allow these crops to grow so their roots break up the soil and their leaves protect it from compaction and erosion.
  • Turn the legumes, mustard and other species into the soil before flowering, where they will break down, further improving soil fertility by adding nutrients and carbon. After a few weeks, turn the soil over again to aid decomposition, much like turning the compost heap.
  • Avoid working soil if it is overly wet.

Winter in northern Australia is known as the dry season. This is the time to carry out garden jobs that have been put off due to the preceding wet season. It is also often the most productive period for growing vegetables and flowers. As temperatures remain high, plants and soil must be protected from the heat. Here are tips to help soil through the dry season:

  • Ensure there is always moisture in the soil. Check soil moisture by putting your finger into the soil. It’s a good indication of whether additional watering is needed. If it feels dry, it needs watering. If it feels moist, then it’s fine.
  • If soil is dry and water repellent apply a soil wetter such as Seasol Super Soil Wetter & Conditioner. This helps to ensure water goes down into the soil to the roots, where it’s needed.
  • Winter or the dry season is also a time to improve the soil in preparation for spring or the upcoming wet season. Apply well-aged compost and manure to rejuvenate your soil before planting. If you don’t have your own compost, purchase it in bags from hardware and garden centres. Look out for Seasol Super Compost or Seasol Garden Mix. Cover the soil surface with mulch.
soil TLC tips in summer
Ensure water gets to where your plants need it banne

Spring soil care

This is the season when the garden comes alive and bursts into spring growth. If you have prepared your soil in advance, now is the time for spring planting. If you haven’t prepared your soil follow tips for ‘Autumn soil care’ concentrating on these key strategies:

  • Remove weeds and lightly dig over the soil to break up any crusting and clumps.
  • If the soil is dry, water it, observing that water soaks in. If the water pools on top or runs off without soaking in, it is hydrophobic. Applying a soil wetter such as Seasol Super Soil Wetter & Conditioner helps overcome water repellency. It also contains liquid compost to add much-needed soil conditioning.
  • Apply well-rotted manure and compost to the soil. Use your own or purchase bagged products such as Seasol Super Compost or Seasol Garden Mix.
  • If possible, let the soil rest for several weeks before planting.

Summer soil care

This season can range from scorching heat and dry to pounding rain and everything in between. Dry weather can cause crusting on the soil surface and a loss of healthy microbial activity within the soil. Unprotected soils heat up rapidly and bake in the summer heat, which can reduce or limit nutrient uptake by plants. Sandy soils in particular, heat up very quickly and loose water fast often becoming hydrophobic (water repellent). Clay soils may become hard and difficult to work when summers are hot and dry. Conversely, heavy rain can cause erosion and leaching of nutrients from all soils. Waterlogged soils are also difficult to dig.

Here are some key factors to help protect your soil in summer:

  • Get and keep moisture in the soil. If water runs off or pools on top, the soil may be hydrophobic (water repellent). Apply a soil wetter such as Seasol Super Soil Wetter & Conditioner to break down the waxy coating that’s formed on the soil to allow water to penetrate. The soil conditioner promotes the development of good soil structure and increases its water-holding capacity. It also helps to oxygenate the soil and improve retention and plant uptake of essential nutrients.
  • Check soil moisture by putting your finger into the soil. If it feels dry, it needs watering. If it feels moist, then it’s fine. Check your garden daily in summer, especially if temperatures are high. In very hot or dry, windy conditions, plants may need twice daily watering. Not only does watering the garden help plants grow, it also keeps soil moist and microbes happy and healthy.
  • Water early morning or late afternoon when there’s less evaporation. However, if a plant is in need of water, provide it no matter what the time of day. Give the garden a deep soak rather than a light water, so moisture can penetrate the soil. Note: If water restrictions are in force, check the recommended ways and times to water.
  • Check automated irrigation systems are working but remember to turn them off if summer is wet to avoid water logging and wasting water. Rain doesn’t get to all areas so manually water areas that are dry, such as containers and garden beds under the eaves.
  • Add well-rotted compost and manures to the soil to improve its structure and fertility. In the warmth of summer microorganisms break down organic matter incorporating it into the soil. Use local material or buy it in bags from your local hardware or garden centre. Look for Seasol Super Compost, which is ready to use and contains high-quality, composted, raw ingredients to revitalise soils to maximise plant growth.
  • Keep soil and roots cool with mulch. Organic mulches protect soil from heat and heavy rain and also add nutrients as they break down. Mulch can also help to prevent water evaporation to retain soil moisture and deter weed germination.

There are many types of mulch. Some, such as sugar cane mulch or pea straw, break down quickly, adding nutrients. Others, such as pine bark or wood chips, are coarser and long lasting but as they are slow to break down do not improve soil structure. Apply mulch no more than 5-7cm thick so water can still penetrate and remember to keep it away from the tree trunk and plant stem.