Frequent fall topics: soil, compost and bulbs

There are still many activities in the yard that could be covered, but I am picking three timely topics to cover this week. They all have to do with one thing: soil.

Soil Tests

Fall is the best time of year to take a soil test. Soil tests can help you find out more about what your plants get to grow in and what major nutrients are available. Fall is preferred as the soil has reacted to anything you have put down during the growing season and the results will reflect that. Soil pH is a very important part of the test. With the right pH levels, plants are able to get the food they need easily on their own. In general, if your soils have a pH between 6.0 and 7.0, you are in good shape. Higher or lower than that and nutrients get tied up in the soil and may not be available for plant growth.

Your soil test also will reveal the levels of major nutrients like Phosphorus and Potassium, and some also will give you the Nitrogen level too. Phosphorus (P) and Potassium (K) are often in adequate supply in our soils, and we really will not need to add more, but the soil test is the only way to know for sure. P and K are stable in the soil and are not moved much by soil moisture. However, Nitrogen (N) is water soluble and we monitor that level by knowing how much we apply during the season. Yes, a soil test can provide you the level of N, but it is only as good as the day you took the sample.


Going along with a soil test is using composts to provide organic matter that contains the N, P, and K, along with 17 or so micronutrients that all plants need. It is a good idea to use composts as they are acidic in nature, helping to keep the pH between 6.0 and 7.0. You can get a compost pile going with the “green and brown” parts from your yard as you clean up for the winter. Brown and not-so-brown plant parts (two parts green to one part brown) can be mixed along with a few shovelfuls of garden soil or soil from a landscape bed, so the decomposition process gets going. This can be just a pile behind the shed or a spot in or next to the garden, or it may be in composting structures you buy or build. You do not want to add weeds containing seeds, as these will be spread throughout the yard as you use your compost. It will take several months to get compost, but once the process starts, it is easy to add to the top and take the good stuff from the bottom. The finer you chop up the plant parts, the sooner it will be compost. Do not forget to keep the compost pile or bin moist.


While you are out in the yard preparing for winter, consider preparing for 2021 by planting colorful spring bulbs. Spring bulbs can be planted until we cannot dig in the soil. Bulbs planted now will have plenty of time to establish a root system yet this fall. The spring bulb has everything ready to go for next year, they just need a place. Bulbs can be planted individually or in groups. Incorporating organic matter into the planting area will help establish the bulbs and give them a great start for 2021 and into the future.

As you can see growing plants is all about the soil. Find a list of soil testing labs here.

About the author: Richard Hentschel’s expertise extends across several subject areas with specialties in lawn care, fruit tree production, woody ornamentals, and home and community gardening. During his 45-year career in horticulture and agriculture, Hentschel became a well-known and respected expert for commercial and homeowner audiences, industry organizations, and media. He retired from University of Illinois Extension in April 2022 with nearly 30 years of service as a Horticulture Specialist and Educator in northern Illinois.