April 2024 Newsletter

Don't forget to join us for Get Wet, our kick off to the 2024 water gardening season!

Get Wet will feature a presentation from Tamara Kilbane, Denver Botanic Gardens' Curator of Aquatics, about how to choose and care for plants for your own water garden.

Pontabbs will be available for purchase at the event and attendees will also have the chance to win door prizes including aquatic plants and day passes to DBG.

Get Wet will be held in Gates Hall at Denver Botanic Gardens from 6:00 pm - 8:00 pm on Thursday, April 18th. We hope to see you there!

By: Dorothy Martinez

Just when temperatures are warming up and you get the itch to go outside and work in your pond, a spring snow storm hits, and the next thing you know you are out shoveling a foot of snow instead of gardening. This is what makes spring gardening so challenging in Colorado. As the saying goes “If you don’t like the weather, wait five minutes and it will change”. This has been especially true this year with two larger snow storms to hit in the latter part of March.

So, with these radical fluctuations in temperature and precipitation ranging from rain to snow and everything in between, how do you get anything productive done in your pond? Well, for starters, you don’t want to put anything tropical or frost tender out before mid-May, as nighttime temperatures are not warm enough yet. This is why you save your serious transplanting outside until after Mother’s Day. This is effective most of the time, but it has snowed as late as May 20th, so keep in mind it’s a rule of thumb but it’s not fool proof.

Things that are safe to do this time of year are cleaning your pond, dividing and repotting hardy water lily rhizomes, and dividing and repotting hardy marginal plants.

For hardy water lilies, once they have been divided and replanted, you can place them back on the bottom of your pond where they will be protected from the elements. Hardy marginal plants (iris, hardy thalia, pickerel rush, sedges, cattails, etc.) are safe to divide and replant as they are still in a semi-dormant state. Once temperatures begin to warm and are consistent, the hardy marginal plants will start to green up and thrive. Something that is helpful when dividing and repotting your hardy marginal plants is to add a timed-release fertilizer (Landon’s Aquatic Fertilizer or Osmocote) to the soil. When potting, be sure to mix the fertilizer with the bottom third of the soil to avoid burning new growth. The timed-release fertilizers allow the plant to have a reliable food source for most of the growing season without the need to add more fertilizer throughout the season.

If you put cannas in your garage or another area that was protected from winter’s freezing temperatures, now is the time to divide and repot those as well. Unlike your hardy marginal plants, once you have divided and repotted your cannas, you will need to place them in a sunny area inside until all threats of frost are gone. Cannas should be moved outside in early to mid-June when night time temperatures are consistently above 50 degrees.

If you stored and saved your tropical water lilies, it is time to see if they have produced any tubers. If they have, you can rinse and clean the tubers in clean water, place them into a Ziploc bag and float them in a heated tub. An aquarium heater is an easy and affordable way to heat the water. Once the tubers start to add numerous leaves, they are ready to be repotted. Keep them inside in heated water until the first part of May, then unplug your heaters, so the plants can acclimate to cooler water temperatures, and then wait until night time temperatures are consistently above 50 degrees before moving them outside.

It is best to wait until after there is no more threat of frost to divide your tropical marginal plants. They do best when divided and repotted in mid to late April, then move them to a sunny locale inside to let them get settled and grow. Tropical marginal plants can also be moved outside when night time temperatures are consistently above 50 degrees.

Now that we are entering April, here’s hoping we have more spring-like days instead of winter-like days. I am looking forward to another productive gardening season!

The Spring Plant Sale at Denver Botanic Gardens is always a fun way to celebrate the beginning of the gardening season. Come visit the Aquatics booth, which will be located just east of the Monet Pool, on Friday, May 10th and Saturday, May 11th from 8:00 am to 4:00 pm each day to stock up on plants and planting supplies for the season! Arrive early for the best selection, or purchase a ticket to the popular Preview Party on Thursday, May 9th from 4:00 pm to 7:30pm on the DBG website.

CWGS members will be staffing the booth again this year and look forward to answering any questions you may have about your water garden. If you’d like to sign up for a plant sale volunteer shift, we have a few slots remaining.

Please contact Brenda Parsons-Hier at (303) 278-2106 or moose.4bph@q.com or Tamara Kilbane at tamara.kilbane@botanicgardens.org with any questions or to sign up for a volunteer shift.

The following article was reprinted with permission from the IWGS Journal archives, Spring 2014, Vol. 29, No.1

​ Spring is simply the most exciting time of year. As things slowly awaken from their winter hibernation, there are some things that you can do to make sure your water feature gets off to a good start this spring.

Does your water feature need a full clean-out this season or does it just need to be tidied up a little? There are a couple of things that you can look for to help you decide. First, if there is a layer of “crud” at the bottom of the pond and the water is dark in color, it would be a good idea to do a full clean-out. On the other hand, if there is just a small amount of debris that you can stir up and capture with a net and the water looks clear, a little tidying up is all that’s in order.

Plan on spending a half to a full day to complete a pond clean-out. A pondless waterfall will take considerably less time. The best time to perform a pond clean-out is the early spring, before your water garden completely awakens from its winter dormancy – ideally before the water temperature in the pond creeps above 55º F. If a clean-out is erformed when the water is warmer, after bacteria colonies form, the balance of the ecosystem will again be thrown off and your pond will go through another “green phase” before the bacteria colonies re-establish themselves again.

Here’s what you’ll need to get started:

• A clean-out pump with approximately 25 ft. of discharge hose

• A high-pressure nozzle for your garden hose, or a power washer

• Garden shears for trimming plants

• A child’s swimming pool or a similar sized container to hold fish and any other critters you find during the clean-out

• A net or something similar to place over the fish container to keep them from jumping out

• Two five-gallon buckets to collect leaves and debris

• A fish net

• A pond detoxifier to remove chlorine and chloramines prior to putting fish back

• Cold water beneficial bacteria

Here are the basic clean-out steps:

• Place the clean-out pump in the deepest point of the pond in order to remove the water.

• Drain the water into the surrounding landscape. Be sure to relocate the pipe two or three times to allow the water to seep into the ground and not flood the yard.

• If you have fish, use some of this pond water to fill up the holding pool. The fish can be removed from the pond using a net once the water is low enough so you can easily catch them.

• Don’t keep the fish in the holding pool for more than several hours. Keep them in a shady spot with a net over the top of the pool to prevent them from jumping out.

• Rinse the inside of the pond. You can also use a pressure washer to help remove debris from the rocks and gravel.

• Don’t try to scrub all of the algae away. Some algae on the rocks will prove beneficial in developing your ecosystem. For an average size pond (11' x 16') this should take around 15 minutes.

• Use the gentle stream from a garden hose to rinse the rocks and gravel. Start at the top and work your way down to the bottom. Periodically turn the clean-out pump on to remove the dirty water. You can discontinue the periodic pumping once the water rinsing down to the bottom begins to look clear. Remove the pump and begin filling the pond.

• Remove any debris from the bottom of the skimmer and vault. This can be done by hand or by using the clean-out pump.

• Remove the media nets and filter pads from the filter. Once the filters have been removed rinse them free of accumulated debris.

• The filter media and mats can be put back into place and the waterfalls pump can be reattached in the skimmer or vault.

• If you’re on city water, it’s imperative that you add a pond detoxifier to the water so it is safe for fish.

• Dip a five-gallon bucket, or similar sized container, in the holding tank and fill it with water.

• After you’ve caught a fish, place it in the bucket and set the buckets in the clean water.

• After about 15 minutes, periodically begin splashing some pond water into the bucket.

• By now, the temperature of the pond and the bucket water should be close to the same. You are ready to spill the fish into their spring-cleaned home.


Article Source: Aquascape, St. Charles, IL, USA (www.aquascapeinc.com)

By: Dorothy Martinez

This spring has brought many changes to the water features located in the lower part of The Hudson Gardens & Event Center’s property.

Starting in late January, large construction equipment was brought in and began the process of renovating the large main lake. The first step was to drain the Overlook, Cascades, and main lake. Within two weeks, large back hoes and earth moving equipment were busy dredging out the main lake. It was a constant parade of loading side dump trucks with all of the muck and soil material from the lake, the trucks driving about 5 miles south of Hudson Gardens to dump the material, and then returning back to be loaded again. This process took the better part of February to complete. In addition, finely crushed granite was added to Bob’s Pond to level the planting area for ease of adding plants along its margins.

The next step was to remove all of the vegetation along the main lake’s edge. There were piles of debris stacked larger than the trucks there to haul away the debris. This process took about 2 weeks.

In early March, work began on renovating the Cascades. Much of the existing Cascades had to be completely redone, as the vegetation (cattails, willows, iris, and grasses) had nearly filled the old streambed. For several years now, the streambed was so choked with vegetation that the water flow was down to a trickle when flowing. Meanwhile, work continued on the main lake with grading and the addition of a very large concrete water intake vault. It took the better part of March to complete this process. The latter part of March has been spent relining the streambed with EPDM liner, river rock, and decorative granite boulders.

April will see the addition of planting beds for water lilies on the west edge of the main lake and also the edges that abut Monet’s Place. Once the grading is complete, EPDM liner will be added to the main lake, river rock added to the bottom and sides, and finally finely crushed granite will be added along the margins for ease of adding and maintaining plants there.

The construction is due to be completed by the end of April, but with the two large snowstorms in March, I would guess the process will likely be finished some time in May. South Suburban Parks and Recreation now manages Hudson Gardens and has been very proactive in this whole process. We are looking forward to how the renovated water features will look with the completion of this project.

We are hoping to renovate the Holding Pond next year. This process will see the addition of a filtration system, the demolition of the fencing currently there, and the addition of seating around it similar to the Victoria Pond. We would like this feature to become a tropical lily display pond during the summer and remain as our holding area for plants in the fall and winter.

Come by later in the summer and check out how the new and improved water features located in the lower part of Hudson Gardens look.

By: Vicki Aber

The CWGS Plant Sale isn’t until the first weekend in June, but it will be here before we know it.
The Plant Sale Committee has been busy deciding what plants we will order. We also have some cannas we planted in 1-gallon containers that will be up and growing well by the time of the Sale.

We usually have many plants donated by our wonderful club members for the Sale. These are usually harvested from home ponds, so are proven hardy. We can always use more, so if you are dividing plants this spring, save some for the Sale.

We also get great plants donated from Hudson Gardens and Denver Botanic Gardens which really rounds out our offerings.

We also will have PondTabbs fertilizer and a variety of pamphlets to help you be successful.

There will also be several very knowledgeable members that are just waiting to have their brains picked.

The Sale is June 2nd at Hudson Gardens. CWGS members have the first hour from 9:00 am to 10:00 am to shop and then the Sale is open to the general public from 10:00 am to 2:00 pm.

If you have any questions or suggestions or requests for particular plants, please contact me.
Vicki Aber 303-423-9216 or docvicki@msn.com.