Sustainable Turf - An Interview with Thomas Bolles

Thomas Bolles works with the Virginia Cooperative Extension (VCE) and specialises in the areas of sustainable turf and sustainable vegetable gardening. We were fortunate enough to interview Thomas, and found out some really interesting information about sustainable vegetable gardening that we can implement in our own back gardens.

Our Interview with Thomas Bolles

1. You work with the Virginia Cooperative Extension, and specialise in sustainable turf and sustainable vegetable gardening. What drove you to focus on these two areas?

I grew up with an interest in plants and animals. I can remember experimenting with growing plants at a young age. I think I began around 10 with some popcorn I’d stolen from the cupboard. I’ve enjoyed successes and failures – or rather “learning moments” in the garden ever since.

Being more sustainable grew out of that. As I got older I realised we’re losing arable land and gaining population. We need sustainability to get the most out of the resources we have long term.

Turf is a different story. For much of my life, I’ve viewed turf as a waste of space and resources that could be otherwise used for more interesting “useful” grasses. Since coming to VCE, my perspective has changed somewhat. In and of itself, turf isn’t terribly sustainable in most cases. When managed appropriately, however, it can be an important tool for protecting water quality and contributing to air quality.

The area in which I live has a large transient population because of the government. We also have a good percentage of new home owners. In both cases, they often don’t understand how to manage turf in our climate. Living in the Chesapeake Bay watershed, managing turf for low inputs while maintaining reasonable quality is an important part of protecting the bay.

The focus of my work on turf is educating people to work with the plant to minimise inputs while maintaining turf that protects against erosion and nutrient loss.

2. Part of producing sustainable turf is knowing about the weeds, insects and diseases that can damage your lawn and spotting them before they do cause any real harm. Is there anything you can do to make sure you identify these as soon as possible?

Pest ID is an important step in pest management. We encourage homeowners to scout their lawns. We also offer educational classes on weed ID.

The turf program I run uses volunteers to measure turf area, soil sample and help ID weeds for homeowners, communities, houses of faith and government agencies. We also educate people about the positives of some “weeds” – like clover – and why they might want to keep these plants in their turf ecosystem.

3. What are some of the methods we can use to ensure our turf is sustainable? Are there any best practice techniques you could tell us about?

  • Mow appropriate to the turf species to promote turf health and suppress weeds.
  • Never mow more than 1/3 of the leaf height at a time to reduce stress and increase recovery time.
  • Soil test to know what nutrients are in the soil before you amend it.
  • Make sure the pH is right for the turf – again, soil test to find out how much lime you need, if any at all, before applying it.
  • Fertilise at the right time of year for the turf species – cool season grasses in the fall and warm season grasses in the summer.
  • Return grass clippings to the lawn to recycle nutrients.
  • Maintain a significant percentage of clover in the lawn to convert atmospheric nitrogen to plant useable nitrogen in the soil.
  • Allow cool season grasses to go dormant in the summer.
  • Regularly amend the soil with organic matter (like compost) to improve the soil. For me, this is critically important. Organic matter helps improve soil health. Soil health is vital to sustainability. Soil health is maintained by having a rich and diverse soil ecosystem.

The“microherd” of micro and macroscopic organism that live in a healthy soil build and maintain good soil structure to allow water and air infiltration, habitats for microbes and room for roots to grow.

Many soil organisms play key roles in cycling nitrogen, phosphorous, carbon and other nutrients. Some organisms form symbiotic relationships that extend the reach of plant roots. Some organisms are predators to plant pests.

Applications of organic matter help feed and sustain beneficial soil organism populations.

4. What is the importance of variety and diversity in sustainable vegetable growing?

Part of sustainability is mimicking nature where possible. Monoculture is not a natural state. Natural settings have a mix of species and are self-sustaining.

No one is fertilizing forests or native grasslands – why? Because there is balance in those ecosystems and they are self-sustaining.

Diverse communities at, above and below the soil surface keep the ecosystem balanced to support the endless cycling of nutrients.

5. What is it in inorganic practices that causes the destruction of essential soil organisms? Can this be combated by implementing organic practices if inorganic practices have been used in the past?

I don’t like the term organic. Organic has too many definitions. Chemically speaking, gasoline has carbon and is therefore organic – but I wouldn’t use it on my veggies. Conversely, water has no carbon and is inorganic.

I think it’s important to look at all practices as tools. We encourage people to use practices that reduce inputs and work with nature.

It’s important to understand that organic farming/gardening doesn’t mean no chemicals. There are many naturally derived chemicals that are toxic and need to be stored, mixed, applied and disposed of appropriately – just like synthetic pesticides.

Organic pesticides still kill things. Most organic herbicides, for example, are broad spectrum herbicides. They will harm a tomato or chickweed without discrimination.

Over use and inappropriate use of synthetic fertilizers and pesticides can have a negative effect on soil organisms. Soil testing, understanding what nutrients plants need and when they need them can help reduce fertiliser requirments (both organic and synthetic).

Understanding plant pests and scouting for them can help stop a potential problem before pesticides are needed. Knowing the difference between beneficial insects and pests can also help you recognize when nature is on top of a pest issue.

But sometimes synthetics are needed. I have been in situations where a herbicide was needed to control an aggressive weed. Once controlled, that area could be weaned off synthetics.

Some practices are neither organic nor inorganic. Conventional agricultural tillage – ploughing of fields – is used by organic and non-organic farmers and gardeners, yet it is a very destructive force on soil organisms. It’s like an earthquake for us. Every time soil is disturbed, it kills, injures and destroys the habit of soil organisms. Sometimes tillage is needed, but with judicious use of tillage and proper aftercare we can help restore soil organism populations.

Organic matter is food for many soil organisms. Adding organic matter into the soil every time you till helps speed the recovery of these populations.

Switching from a reliance on synthetic inputs to more sustainable practices can, over time, build soil organism populations. Using cover crops to keep living roots working with microbe populations, utilizing diverse plant species, minimizing soil disturbances and increasing soil organic matter will improve the health of the soil ecosystem.

6. Sometimes soil can be of a poor quality, which can inhibit plant growth. Are there any ways that this can be combatted?

Poor quality soils are very common in urban areas. Development often causes top soil to be stripped away and subsoils are then compacted to make a stable platform to build upon. Throw in some cut and fill as the site is graded and you can end up with all sorts of soil issues.

Encouraging and nourishing the organisms that live in the soil is a way to let nature restore itself.

A properly functioning soil ecosystem can drastically improve the quality of a poor soil in terms of structure, infiltration and fertility. How is this achieved? It starts with trying to jump start the soil biota by supplying organic matter to soil. Then you maintain conditions that encourage the life in the soil.

This is done by:

  • Minimising soil disturbance
  • Energising the soil with diversity of plants
  • Keeping the soil covered year-round
  • Maximise living roots

What makes up a bio-intensive garden bed?

Generally speaking, a bio-intensive system involves a lot of plants in a dense area. Plant spacing is much tighter than traditional row systems. This works well in a deep soil, rich with organic matter. For most people, that’s not what they start with.

Where I live, we have a lot of compacted soils almost devoid of organic matter. One of the methods we recommend for transforming the soil is double digging. This is a process of digging down 12 inches and cracking the soil another 12 inches. Compost is incorporated to create a fluffier soil.

I said earlier that soil disturbance was bad for soil organisms. This is a case of disturbing the soil to improve it by adding organic matter to improve the structure and nourish nutrient cycling organism in the soil. We have a demonstration garden where we have done this. Compost is regularly added and serves as the only input.

In an intensive system, crops are managed so that one crop follows another throughout the year. When a food crop is not being grown in a bed, cover crops are used to keep the soil active. Crop families are rotated and companion crops are utilised to reduce pest issues. Pests are regularly scouted.

In our demonstration garden, we’ve chosen not to use pesticides, so if we can’t spot a severe infestation before it occurs, removing the plants is our big stick.

However, I think it’s fine for people to use pesticides as a tool of last resort – provided they have identified the pest and are using a product labelled for that pest correctly and at the right time.

Part of our education process is helping people understand integrated pest management – scout, ID, determine if controls are really necessary, and start with the most benign options.

7. What is farmscaping? Could we do this in our own back gardens?

Farmscaping is the idea that you devote some of your garden to plants then attract pollinators and other beneficial insects. This can be done on a grand scale or even on a patio where all the plants are in containers.

8. Does companion planting play a large part in sustainable vegetable gardening?

They don’t need to be, but they do help. Companion planting can help with pest control (carrot pests don’t like onions and onion pests don’t like carrots), pollination (dill can draw in pollinators for tomatoes) and fertilisation (pole beans can use maize as a structural support and will help supply nitrogen to maize).

Sometimes space can be an issue and sometimes it’s easier to figure rotation and harvesting schemes when you don’t worry about companions – especially for beginning gardeners.

9. For sustainable turf, how important is it that you calibrate your sprinkler system so that your lawn receives the right amount of water?

If you use irrigation, calibration is important to make sure you are applying the right amount of water. Too much is wasteful and may encourage disease by leaving the blades wet too long. Not enough water will stress the plant. It’s also important to water at the right time of day (early morning) to reduce evaporative loss and allow the blades to dry more quickly.

Ultimately, like any other part of the landscape, selecting the right plant for the right place is an important part of sustainability. Depending on the climate, season and species of grass, irrigation may not be necessary in a home lawn situation.

In my area, for example, with an established tall fescue lawn, nature usually provides enough rain for the turf when it is actively growing – assuming you allow the turf to go dormant in the summer.

Cool season turf will naturally go dormant in hot, dry weather if you don’t irrigate it. The turf may brown, but if it’s healthy and mowed properly it will usually survive and rebound a lush green in the autumn as rainfall increases and temperatures decrease.

Except in cases of severe prolonged drought, tall fescue in my area really only needs irrigation when it’s being established in my region. In more arid areas, even drought resistant warm season grasses may need irrigation throughout the year.

As a final point, I think it’s important to understand that sustainable practices are tools. There’s a bit of trial and error to find out what works for you in your garden. Sustainability is not an absolute. It’s more about moving towards sustainability.

Not everyone can, is comfortable with, or has the skills/knowledge to implement all sustainable practices and become totally sustainable in their gardens and landscapes – and that’s okay. It’s not an all or nothing proposition.

The Virginia Cooperative Extension is one of many around the United States, each working towards the same goal in different ways and specialising in different areas.

We hope that you've enjoyed this incredibly informative interview with Thomas and that it's inspired you to spend even more time in the garden. Remember, Shedstore is the UK's premier supplier of everything to do with the gardenPlease click here to view our fantastic range of gardening products today.