The Importance of Knowing Your Temperatures, Moisture & pH Levels

Author: The ilikeseeds team  

A Must Know For Any Gardener

The Importance of Knowing Your Temperature, Moisture & pH Levels.

Soil Temperatures

Soil temperature is the factor that drives germination, blooming, composting, and a variety of other processes. Learning how to check soil temperature will help the Australian gardener know when to start sowing seeds. Knowledge of what is soil temperature also helps define when to transplant and when to begin a compost bin. Determining current soil temperatures is easy and will help you grow a more prroductive and pleasurable garden.

What is Soil Temperature? So what is soil temperature? Soil temperature is simply the measurement of the warmth in the soil. Ideal soil temperatures for planting most plants are 18 to 24 C. Nighttime and daytime soil temperatures are both important.

When are soil temperatures taken? Soil temperatures are measured once soils are workable. The exact time will depend upon your climate zone. Warm, Tropical and SubTropical zones, the soil temperature will warm up quickly and earlier in the season. In Moderate zones, the soil temperature may take months to warm up as winter chill wears off. 

Most people don’t know how to check soil temperature or what tools are used for taking accurate readings. Soil temperature gauges or thermometers are the common way to take the reading. Just use a soil thermometer is all you need. In a perfect world, you would check nighttime temperatures to ensure they are not so cold your plant’s health will be impacted. Instead, check in the early morning for a good average. The night’s coolness is still mostly in the soil at this time. Soil readings for seeds are done in 3-5cm of soil. Sample at least 10-15cm deep for transplants. Insert the thermometer as far as you can, or maximum depth, and hold it for a minute or two. Do this for three consecutive days. Determining soil temperatures for a compost bin is also done in the morning. The bin should maintain at least 16 C. Bacteria and organisms will then do their work.

What are ideal Soil Temperatures for Planting

The perfect temperature for planting varies dependent upon the variety of vegetable, flower or fruit. Planting before it is time can reduce fruit set, stunt plant growth and prevent or reduce seed germination. Plants such as tomatoes, cucumbers and snap peas benefit from soils at least 16 C. Sweet corn, lima beans and some greens need 18 C. Warmer temperatures into the 20s C. are required for watermelon, capcicum, squash, and at the higher end, cantaloupe and sweet potatoes. If you are idon't know check your seed packet for ideal soil temperatures for planting. Realistic Soil Temperatures Somewhere between the minimum soil temperature for plant growth and the optimum temperature is the realistic soil temperature. For instance, plants with higher temperature needs, such as okra, have an optimum temperature of 32 C. However, healthy growth can be achieved when they are transplanted into soils of 24 C. This happy medium is suitable for beginning plant growth with the assumption that optimum temperatures will occur as the season progresses. Plants set out in cooler zones will benefit from late transplanting and raised beds, where soil temperatures warm up more quickly than ground level planting. 


PH levels Recomendations

The pH of soil or other mediums directly affects nutrient availability to plants roots. Plants thrive in different soil pH ranges, but readings outside 4 to 8 are rare. Some plant species are tolerant of wider pH ranges, but most prefer a neutral soil with pH levels falling within the 6 to 7 range.

Increasing Soil pH

A common practice is to apply finely ground agricultural limestone. Depending on your soil type, different amounts of limestone will be required to increase the soil pH value.

Decreasing Soil pH

Adding organic material such as highly acidic sphagnum peat moss will lower soil pH. Introducing elemental sulfur (90 or 99% sulfur material) or acidifying fertilizers such as ammonium sulfate with repeated use can also reduce soil pH.

Recommended Soil pH Levels

Please take a look at our recomended plant pH Level Charts for all the information you need. Here's a look at our Vegie pH Level Chart. If your looking for the best possible answer, our new Deluxe Digital Readout Soil Ph Tester.


Moisture Levels Recomendations

Moisture levels reqired vary depending on soil type, plant, current weather changes. Here are a few important things to know.

Soil Types and Watering Information

Loam Soil: Very porous and retains moisture well. This is the optimal soil type and can be watered normally.

Sandy Soil: Extremely porous and drains quickly. Water slowly to saturate soil root zones.

Clay Soil: Holds more water, but is slow to absorb and release. Do not water faster than the soil can absorb it.

General Soil Moisture Information & Tips

  • If you have sandy or very heavy clay soils and would like to improve its water retention, add compost or organic matter to your soil.
  • Adding sand to clay soils, or clay to sandy soils will create a cement-like soil, making water retention worse.
  • One inch of water per week is adequate for most plants. You may use a rain gauge to assist.​
  • All vegetables require soil moisture between 41% - 80%.


Recommended Soil Moisture Levels

Please take a look at our recomended Moisture Level Chart for all the information you need on each plant. Here's a look at our chart for flowers. Check out our new Deluxe Soil Moisture Tester product for all your moisture level solutions. 


Happy Gardening.............☃️

The ilikeseeds team.

Leave a comment

Comments have to be approved before showing up