Fall is the best time of year for plant care and maintenance. Spring is too busy with winter clean up, lawn maintenance, mulching, planting and more going on in the surrounding landscape. If a majority of the pond work is completed in the fall then your focus can be elsewhere in the spring. So when you are tired and overheated from other spring garden work you can rest your feet in the water to cool yourself down and simply enjoy the emerging beauty in the garden pond as it comes back to life.
Over wintering tropical plants indoors should occur no later than early September. If they get moved in too late they have been exposed to the cool night temperatures that may set their clocks in the direction of hibernation. Most tropical marginal plants will winter just fine in anything from a decorative no-hole container to a bucket or dishpan. They not only add interest to the indoor environment but they add some much necessary evaporative moisture to the dry environment of the heated house of the northern climate.
Tropical lilies can be wintered indoors as well and there are a number of different methods to accomplish the goal. The best instructions I’ve ever seen are in Greg and Sue Speichert’s Encyclopedia of Water Garden Plants that is also the best aquatic plant book I’ve read. It contains more useful plant information than several other books combined.
Late August to mid-September is the ideal time to prevent the leading cause of death to pond plants over the winter. Often plants have grown so vigorously over the summer months that they have become completely root bound and starved for nutrients. These weak plants become very susceptible to pests and disease due to their less than vigorous state. Think of it as being run down and getting the flu. You are much better equipped to fend off a serious infection if you are healthy and well nourished. It’s the same for plants except their weakened state may result in death over the winter months.
Any plants that are struggling for space and nutrients should be provided a fall division to provide ample space in the container, fresh soil and temperature release fertilizer (Nutricote) so it will be available when needed early in the spring. The difference is dramatic in the success rate over winter and in the vigor, beauty and increased flowering they will provide you with in the spring. (Lotus should be the only plant that division is reserved for the spring.)
By the time September comes most fertilization should have been discontinued to allow plants to consume the nutrients they require before cooler weather sets in. Some plants are particularly sensitive to unused fertilizer so late feedings may lead to their demise over the winter months. Depending on your area final feedings should be ended in late July for zones 3-5; early August for zones 6-7 and mid-August for zones 8 & 9.
Deadheading and cutting back shouldn’t take place until frost has caused yellowing of the foliage at the very least. Brown is even better. Plants need to retract their energy and store it for the winter months. Prematurely removing their green foliage will weaken them and limit their ability to survive winter. Plants that have particularly sturdy stems may be left uncut for winter interest and plants that have hollow stems should be cut just above the high water level. It limits water from entering through the stems and permitting diseases and/or fungal attacks.
There is also an age-old rumor that plants should be dropped to the bottom of the pond to protect them for the winter months. If they are hardy to a particular zone then they are perfectly capable of sustaining the temperatures that winter may dish out. Dropping them to the bottom can increase the likelihood of their demise over the winter.
I’ve often said “there aren’t any little fairies that go around and move plants in natural ponds down to the bottom for the winter. If that’s where they live then they can take it.”
On the other hand winter sometimes dishes out extreme temperatures and conditions that would be considered unreasonable or extraordinary. In that case you are simply at the mercy of Mother Nature and it isn’t always a winning proposition. However that can always be looked at as an opportunity to get something new! Gardening has long been a lesson in patience and perseverance!
Following all of the recommendations listed above will help to ensure that your plants are not at an additional disadvantage to fail through the winter and you will be rewarded with healthy stunning growth as it unfolds in the spring. Then you can just sit back and enjoy the show!