How should I manage weeds and the orchard floor?
Two surfaces, two jobs — a clean strip where the trees are, and a working floor everywhere else.
The orchard floor is not one surface. It is two, and they have different jobs.
The tree row
- Where your young trees are trying to establish.
- Anything growing there is taking their water, their nutrients and their light.
- Keep it clean.
The row middle
- Your working surface. It carries the sprayer, the mower, the shaker and the harvest trailer.
- At the end of the season it has to let you sweep nuts off it cleanly.
- It can also protect your soil.
Why the floor matters
| What it affects | What it costs you |
|---|---|
| Competition | Weeds take water and nutrients from young trees, and shade them. Worst in the first four years, when the tree has a small root system and cannot compete. |
| Water | Anything green is using water. Vegetation also changes where water goes, and hides leaks and blocked emitters. |
| Soil | Cover protects soil from erosion, crusting, runoff and dust. Bare, repeatedly worked soil loses structure. |
| Access | A stable middle lets you get machinery in after rain. A rutted, cloddy one does not. |
| Animals | Weeds around trunks give cover to voles and mice, which chew bark. Rodents that girdle a young trunk kill it, and rodents chewing drip lines waste your water. |
| Harvest | Tall weeds, loose residue, clods, holes and wheel ruts all cost you nuts at pickup. Once the trees are bearing, that is a direct loss. |
The tree row
Judge the width by where the tree’s roots and water actually are, not by a number. The strip needs to cover the wetted zone the tree is drawing from. It does not need to be wider than that — bare soil across the whole orchard is a cost, not a goal.
Three rules for the strip
- Keep the trunk zone completely clear. This is where voles and mice hide, and where they do their damage.
- Do not cultivate close to the trunks. Disks and other mechanical tools cut roots and strike bark, and every wound is a way in for crown and root disease. Control weeds near trunks by other means, and give your implements a safe offset.
- Check the wetted zone separately when you inspect. Weeds around an emitter change how much water the tree actually receives, and they hide a leak or a blockage until the tree shows stress.
Herbicides on young trees
Young trees are much easier to damage than mature ones, and fewer products are registered for use on them. Which products you can use is decided by your own country’s registrations, and those change every year. Ask locally. What travels between countries is the technique.
- Green bark is not protected bark. A young trunk is still green and can be damaged by contact herbicides. Leave the trunk guard or carton in place for the first two years after planting, or until the trunk gets too thick for it.
- Watch for drift. Branches on young trees are low and easy to hit. Be careful in wind, and check your rig height, nozzle angle and nozzle choice before you start.
- Wait for the soil to settle. After planting, the soil around the tree is loose and the roots are shallow. A soil-applied herbicide can run down a crack or into a loose pocket and reach the roots. Let the soil settle first, and water carefully so you do not wash the herbicide deeper.
- If you are mounding soil for the tree rows, do not do it just after a herbicide application. You will collect treated topsoil into the mound and concentrate it exactly where the roots will grow.
Three steps, in this order
- Identify the weed.
- Choose something registered locally that works on that species.
- Apply it properly, with well-calibrated equipment, at the right growth stage.
The row middle: choosing a system
Five options, and none of them is right everywhere. Find the row that matches your block.
| System | What it gives you | What it costs |
|---|---|---|
| Clean, bare middle | Predictable at pickup, easy to inspect, no live plants using water. Suits flat, low-erosion sites and systems that need a very clean harvest surface. | Repeated tillage roughens the soil, raises erosion and dust, damages structure and builds wheel ruts. |
| Mowed resident vegetation | Whatever grows naturally, kept short. Low disturbance, gives traction, cheap and flexible. | It still uses water, it will set seed if you mow late, and it gives cover to rodents. |
| Planted seasonal cover crop | Sown for a purpose — erosion control, better wet-weather access, soil condition. | Seed, establishment, management and water. |
| Permanent vegetation | Continuous cover and traction, least erosion. | The strongest and most permanent competition. Does not suit young or water-limited blocks. |
| Mulch on the strip | Useful in targeted situations. | Where the material comes from, the cost of spreading it, weed seed and contaminants in it, fire risk, and the rodents it will shelter. Keep it off the trunk itself. |
Mowing
Time it by purpose, not by calendar. Mow early and you stop seed set, but the weeds regrow before harvest. Mow late and you leave cut material lying on the ground exactly when you need a clean surface.
Cultivation
Cultivation still has a place, for annual weeds and for working material into the soil. But a pass that removes every visible weed can still be a bad decision if it leaves clods, ruts, dust, erosion or a wounded trunk.
Annual and perennial weeds are different problems
| Weed group | What controlling it actually takes |
|---|---|
| Winter annuals | Scout early and treat while small. Waiting until the growth is dense makes every option more expensive. |
| Summer annuals | Watch after irrigation and after rain — that is what triggers the flush. Growers who plan only a spring programme get caught by this one. |
| Creeping perennial grasses bermudagrass, johnsongrass | Map the patches, treat at the stage when the plant is moving reserves downward, and be careful not to drag fragments to clean ground on your implements. One treatment is not control. |
| Deep-rooted perennial broadleaves field bindweed | Repeated, species-specific work. Treating the tree row while ignoring the field boundary just delays the return. |
| Nutsedge and other wet-ground weeds | Fix the water as well as the weed. Where you find nutsedge, look for the leak, the over-watered zone or the drainage problem underneath it. |
Cover crops
A cover crop can do real work for you: more organic matter, less erosion and runoff, less crusting and dust, better access in the wet season, and some suppression of winter weeds. Legumes add some nitrogen.
Before you sow
- Budget its water. The question is not whether cover crops are good. It is whether this block can carry one without taking water from the trees. Competition matters most in young orchards, on shallow soils, where irrigation capacity is limited, and in dry years.
- Do not grow a cover on the tree row of a young orchard. Summer water competition against a young tree is the one thing to avoid. Keep the cover in the middle.
- Sow in autumn, so the cover uses the season’s own light and water rather than yours.
Once it is growing
- Kill it early enough. Terminating the cover around May reduces early-season water stress on the trees. Where you have no irrigation to spare, work the cover into the soil in spring so the water goes to the trees.
- It suppresses weeds. It does not replace weed control. No orchard with a cover crop is weed-free. Keep the tree strip programme and the patch programme running.
- Do not credit yourself a fixed amount of nitrogen from a legume. What you get depends on the species, how much biomass grew, and when it breaks down.
- Mow it, or you will grow gophers. An unmown cover is excellent gopher habitat. If you use covers, your vertebrate pest monitoring has to be better, not the same.
What to do at each orchard age
| Orchard age | What belongs in the middle |
|---|---|
| Years 1 and 2 | Clean tree rows are the priority. Keep anything in the middle low-risk and water-budgeted. |
| Years 3 and 4 | Try controlled vegetation in selected middles where water and traffic allow it. Do not commit the whole farm before you have seen it work on your own soil. |
| Mature orchard | Use permanent or seasonal cover where your water supply and your harvest system can carry it. |
One honest gap: nothing in our source material names a cover crop species suited to a Turkish, Balkan or Central Asian orchard. The autumn-sowing and May-termination advice above is French. Ask a local adviser what to actually sow before you buy seed.
Building the harvest floor
Mechanical harvest needs a surface you can blow, sweep and collect from without losing nuts or picking up dirt. Tall weeds, heavy residue, clods, ruts, holes, damaged berms and leaks all cost you at that moment.
| When | What to do |
|---|---|
| Through the season | Avoid the traffic and cultivation that create clods and deep wheel lanes. Repair damage while conditions allow it. |
| Before harvest season | Walk the block and map ruts, holes, irrigation leaks, tall weeds, perennial patches, woody debris, damaged berms and low spots. Fix them while the schedule is still flexible. |
| Before final floor preparation | Mow whatever vegetation you have kept, early enough that the cut material settles and does not regrow. |
| At final preparation | Smooth the surface without overworking it. Protect drip lines and roots. |
| Just before shaking | Walk it again for debris, new growth, leaks and soft ground. Test pickup in one representative area before you commit the whole block. |
| After harvest | Write down where pickup was poor and why. That is your work list for next season. |
Mistakes worth avoiding
The trees
- Letting weeds compete with young trees. The first four years are when it costs most and when the tree can least afford it.
- Treating the tree row and the middle as one zone. A cover that helps the middle can starve a young tree at the trunk.
- Cultivating too close to trunks. Wounds let crown and root disease in.
- Spraying a young green trunk. Keep the guard on for the first two years.
- Sowing a cover crop without a water budget. It is a crop, and it will take what it needs.
- Leaving a cover unmown. You have built gopher habitat.
The floor
- Cultivating too much. You roughen the floor, raise dust and erosion, and create harvest work.
- Spraying and hoping. Identify the weed, check what is registered, calibrate the machine, treat while the weeds are small.
- Using the same product every year. You are selecting for the weeds that survive it.
- Mowing too late. Cut material lying on the ground is lost nuts at pickup.
- Treating the tree rows and ignoring the ditches and margins. The weeds come straight back.
- Fixing the floor at harvest time. Ruts and clods are cheap to prevent and expensive to repair under pressure.
Choosing your floor system
Eight things to settle for each block
- Is the block in its first four years? If so, the clean tree strip is not optional.
- How much water you can spare for vegetation in the middle — in a dry year as well as a normal one.
- Whether erosion, runoff or wet-season access is a real problem on this block.
- Which machines have to work in the middle, and what surface they need.
- Which weed species dominate, at what time of year, and where the patches and the edges are.
- Whether your mowing and termination plan actually fits your harvest date.
- Whether you have a rodent monitoring plan — especially if you are using a cover.
- What is registered locally for young trees, and whether your operators are trained and your sprayer calibrated.
Work through that list block by block rather than farm-wide. The answers change between a first-leaf planting and a mature block on the same farm, and the whole point of this chapter is that the floor is not one thing.