Dollarweed: Friend or Foe

Dollarweed: Friend or Foe

We have many weeds in the Panhandle that are a nuisance to our landscape, with some being very difficult to control. Dollarweed certainly falls into this category. But, does dollarweed have an upside?

Dollarweed (Hydrocotyle spp.) is a largeleaf creeping perennial that thrives in central and northern Florida, but is found throughout both Atlantic and Gulf coasts. Dollarweed is resilient, as it can reproduce by seed, rhizomes and tubers. The mature plant produces vertical shoots with shiny green round shaped leaves and scalloped edges. The leaves can grow up to the size of a silver dollar, hence the plant’s name. This plant grows low to the ground and thrives in moist environments.

Figure 1: Pennywort (Dollarweed) vs. Dicondra.

Credit: Ramon G. Leon, Darcy E. P. Telenko & J. Bryan Unruh, UF/IFAS

Hydrocotyle umbellate is the species most found in Florida lawns. In city landcsapes, dollarweed can be an indicator of leaking water mains or even septic drainfield problems. It also can be an indicator that you may be over-irrigating your lawn. Hydrocotyle bonarienies or pennywort, on the other hand, is a species that is found on frontal and back dune areas, along with sandy marsh or flatlands. This species is known to help stabilize dunes and assist in combatting dune erosion.

Often, dollarweed is confused with pony’s foot or Dicondra carolinensis. This weed will grow along with dollarweed, as it prefers moist environments as well. Pony’s foot has a distinct difference in leaf structure than dollarweed. Pony’s foot has a kidney-shaped circular leaf, as dollarweed is disc shaped.

How does one control dollarweed in a landscape? Pulling it up by hand can be successful. However, it’s a must to pull all of the white rhizomes from the soil. Otherwise, the plant will rebound quickly. Selective & non-selective herbicides will control dollarweed. However, you must be persistent. Applying a pre-emergent and post emergent herbicide is the best practice when using chemical applications. There are many herbicides on the market that specifically list the control of dollarweed, such as atrazine and 2, 4-D options. Always follow the directions and precautions from the manufacturer when using a herbicide and be sure that the product will not affect your variety of turfgrass. Contact your local county extension office for more information on controlling dollarweed and other pesky weeds.

Supporting information for this article can be found in the following the UF/IFAS publication:

“Pennywort (Dollarweed) Biology and Management in Turf” by Ramon G. Leon, Darcy E. P. Telenko and J. Bryan Unruh: http://edis.ifas.ufl.edu/pdffiles/EP/EP38900.pdf

& “Native Plants for Coastal Dune Restoration- What, When and How for Florida” by M.J. Williams, USDA NRCS: https://www.nrcs.usda.gov/Internet/FSE_PLANTMATERIALS/publications/flpmspu7474.pdf

 

UF/IFAS Extension is an Equal Opportunity Institution.

Don’t Commit Crape Murder

Don’t Commit Crape Murder

Pruning is one of the most controversial aspects of maintaining crapemyrtle. Traditionally, many crapemyrtles are routinely topped, leaving large branch and stem stubs. This practice has been called “crape murder” because of the potential impacts on the crapemyrtle health and structural integrity. Topping is the drastic removal of large-diameter wood (typically several years old), with the end result of shortening all stems and branches.

Hard pruning (topping) stimulates crapemyrtle sprouting from roots, upper stems, or the base of main stems.  If basal and root sprouts are not removed, one or more may form woody stems that eventually compete with existing main stems. These additional or competing stems may result in poor form and structure, such as stems that rub against each other.

Topping typically delays flowering up to one month compared to unpruned crapemyrtle. On some cultivars, topping also shorten the season of bloom. Long-stem sprouts emerge just below large-diameter cuts that result from topping. These sprouts usually develop into upright, unbranched stems that eventually flower, often bending under their own weight. Rain or wind storms can cause extreme bending and some will break because they are weakly attached to the main stem.

Topping removes large amounts of starches and other food reserves stored within branches. Topping dramatically reduces the size of the plant canopy, ultimately decreasing the plant’s ability to produce food (starches) through photosynthesis. The large branch stubs caused by topping result in large areas of exposed wood that allow access by insects and wood-rotting organisms, weakening the plant’s structure. Finally, topping results in many dead stubs throughout the tree.

Proper pruning may be needed, just like any other tree. Lower limbs of crapemyrtle are removed to increase clearance for pedestrians or vehicles. Stems are cut to increase branching. Other pruning may be conducted to direct growth away from structures, stimulate flowering, and remove spent flowers, seed capsules, and dead or damaged branches and twigs.

Properly placed, crapemyrtle is a low-maintenance plant needing little or no pruning. Problems with overgrown, misshapen, or misplaced crapemyrtle can be greatly reduced with proper selection of crapemyrtle cultivars, proper plant selection at the nursery, and proper placement in the landscape. For more information on cultivar selection go to: http://edis.ifas.ufl.edu/mg266.

If pruning is necessary, use the following recommendations:

  • Pruning for safety may be done anytime. This may involve removing damaged or weak branches or pruning lower limbs for pedestrian and vehicle clearance and visibility.
  • Pruning to improve plant structure, redirect growth, or alter plant shape and appearance should occur when plants are leafless and dormant–typically December through February. Although this can be accomplished at any time, without leaves, the branching structure is clearly visible to more easily determine appropriate branches for pruning.
  • Prune to remove crossing or rubbing branches.
  • Prune dead, damaged, or diseased branches at the branch collar.
  • Remove vigorous branches growing toward the center of the canopy.
  • Severe pruning should be performed late in the dormant period. Pruning too early might stimulate new growth that could be damaged by low temperatures.

 

Green Side Up:  Plant Properly to Avoid These Common Mistakes

Green Side Up: Plant Properly to Avoid These Common Mistakes

It is a common misconception that winter is a time of rest in the landscape, for both plants and people.  In the Panhandle, the winter months tend to be rainy and miserable, with wild weather fluctuations in between.  These conditions cause folks to think their chores are done until the weather warms up and plants begin to grow again. In reality, winter lays the foundation for the next year of growth! This is because, though most plants are dormant or have at least slowed their growth above ground, their root systems continue to develop through the cold.  This “catch-up” time when plants are not growing above ground is the ideal time to plant woody trees and shrubs so they can focus their energy on getting a root system established without having to worry about supporting shoot growth!  However, even if you plant at the proper time, several common mistakes can still torpedo your planting efforts.  I once worked for a snarky nurseryman who, when new employees would ask how he wanted trees to be planted, would answer, “Green side up, of course.”  So, remember to plant green side up and also keep the following in mind when you plant this winter!

Cutting circling roots.

  • Digging the right hole. The quickest way to resign a plant to failure before even removing it from the container is to dig a bad hole.  In order to facilitate ideal root development and allow the plant to establish as rapidly as possible, the planting hole should be 2-3 times the diameter of the rootball.  The easiest way to measure this is to set the plant were you want it and begin digging the hole around it; this step allows you to visualize the size of the hole.  Most holes that are “eyeballed” are not wide enough. A little extra digging in the beginning can make a lot of difference later.  In addition, the planting hole should be, at minimum, the same depth as the rootball.  In a perfect scenario, after planting, the top of the rootball should be a half an inch to an inch higher than the surrounding soil to accommodate for settling of the soil underneath the rootball.  This prevents the plant from sitting in a depression that water could pool in, leading to disease issues.  It can be hard to believe, but simply digging a proper hole helps ensure plant establishment and enables long-term survival!
  • Preventing Circling Roots. Often, plants are constrained in a container that is a little too small for a little too long on the floor of a nursery.  When this situation occurs, the roots of the plant do not stop growing once they reach the “wall” of the container, but rather keep going in a circular pattern around the edge of the pot.  This is a problem because, if not corrected, the roots will continue this growth pattern once in the ground, eventually strangling the plant.  However, this problem is easily corrected by severing the circling roots.  This is where gardeners often get squeamish however.   It is time to check your plant conscience at the door and know the plant will thank you later!  I like to make vertical slices, evenly spaced, around the rootball.  These slices should cut about an inch into the rootball to ensure both superficial and unseen circling roots are cut; this somewhat brutal task can be accomplished with a sharp shovel, machete, or even a heavy-duty pair of pruners.  At every cut, the previously circling root will branch, creating a nice web of new roots that will serve as anchors for the fledgling plant.
  • Backfilling Correctly. The single most asked question involving plants trees and shrubs is, “Should I backfill the hole with compost?”  The single most common answer I give in return is, “Absolutely not.”  Although it seems counterintuitive, it is almost never a good idea to backfill with a soil that is not your native soil.  There is a simple reason for this.  If a tree were planted in a hole that is backfilled with rich soil and is surrounded by our infertile, native Florida sands, why would it ever want to leave that hole?  Turns out, it does not want to leave that easy environment because it has all the nutrients it needs right there, which is a problem.  What happens when a drought, hurricane, or other stress event comes calling?  The plant will not have a wide-spreading root system for support and will suffer from lack of water or lodging from high winds.  By backfilling with your native soil, you encourage the plant’s roots to grow out and seek water and nutrients.

As you can see, there is a little more to planting than “green side up.” But, if you plant at the right time, dig the right hole, prevent circling roots, and backfill with your native soil, you will have set your newly bought tree or shrub up for success and will be able to enjoy it for many years to come!  For more information on planting and other horticultural topics, contact your local UF/IFAS Extension office and as always, happy gardening!