16 Dec 2009

Pets and Plants During The Holidays

Enjoying The holidays
Enjoying The Holidays

Have you heard that many holiday plants can be toxic to pets?

The danger is real, but, fortunately, it is often exaggerated.

Poinsettias, holly, and mistletoe all pose some threat to pets. All are toxic in large doses. But for most pets, most of the time, the result of eating your Christmas centerpiece is more likely to be a trip to the dog house rather than a trip to the vet.

Here’s what you need to know:

Poinsettias: The danger from Poinsettias has been greatly exaggerated. The plant has lost most of its toxicity through hybridization. However, this does not mean that poinsettias are edible! The sap from the plants is an irritant.

Symptoms: Excessive salivating, pawing at the head, vomiting

Treatment: Wash off the irritating sap. If your pet’s eyes are irritated or inflamed, or if your pet is vomiting, you may need to call your vet. Some dogs and cats need a medication to calm the irritation.

Holly: The berries are attractive to pets, but they can be poisonous in large quantities. Sharp holly leaves can also cut your pet.

Symptoms: Upset stomach. If your pet is vomiting or has diarrhea, there is a danger of dehydration and electrolyte imbalance.

Treatment: If your pet ate only a few berries, there is probably no danger. However, if you suspect that your pet ate lots of berries, call your vet.  The vet may prescribe IV fluids to treat dehydration.

Mistletoe: (American mistletoe is less toxic – and much more common in the US – than European mistletoe) Pets are most likely to eat the berries, which are poisonous. If your dog or cat eats a large quantity of mistletoe berries, it may become very ill. A few berries produce only mild stomach upset – but lots of berries can be dangerous.

Symptoms: Animals suffering from mistletoe poisoning may show any of these symptoms: hyper-salivating, vomiting, diarrhea, excessive urinating, increased heart rate.  As with holly, if you suspect your pet ate a large quantity of mistletoe berries, call your vet immediately.

Remember: “large quantities” of a toxic plant is a subjective measurement. The size of your pet, its age and overall health, and its sensitivity to environmental irritants all need to be considered. What would seem like “a few” berries for an adult Golden Retriever could be a toxic amount to a cat.

If you are at all worried about your pet’s symptoms, call your vet and follow directions.

Photo by Gabbcan Released under Creative Commons License

09 Dec 2009

Frosty Lawns


A frost coated lawn
A frost coated lawn

Is it safe to walk on a frosty or frozen lawn?

Generally, no. It is better to stay off grass that is frosty or frozen. Your weight can break the brittle blades of grass, driving ice crystals into tissue, which will damage – or even kill – the grass. Come spring, you may find dead patches in your lawn.

Grass that is damaged, but not killed, will be more susceptible to insect damage, moss, and weeds in the spring.

The best course, if possible, is to just stay off the grass until the sun melts the frost.

Even grass covered by snow can be damaged by heavy foot traffic, so be careful when building snowmen or making snow angels.


Grass usually survives winter without any special care.

During the short, cold days of winter, northern turf goes dormant. It stops growing and does not require mowing, watering, or fertilizing. Grass has a high sugar content, which normally acts as a sort of natural anti-freeze, allowing it to overwinter without protection.

You ensure green and healthy turf in the spring by caring for your lawn in the fall.

A good fall regimen for a healthy lawn will:

  • Fertilize with a good, slow release fertilizer that will encourage root growth, rather than top growth.
  • Rake up leaves and grass clippings
  • Top dress with compost
  • Add lime to sweeten the acid soil common in Puget Sound
  • Overseed bare patches

Remember – you are building strong roots and healthy soil. While this is a year-round goal, it is especially important in the fall. Your turf will not only survive the cold but will be thick and green come spring.

This post was Part 4 of a series.
Part 1: Caring For Your Winter Garden
Part 2: Frozen Ground
Part 3: Protect Your Pots

Photo by Xerones Released under Creative Commons License

05 Dec 2009

Protect Your Pots


A Broken Pot Pressed Back Into Service
A Broken Pot Pressed Back Into Service

Sometimes it seems like winter is harder on pots than on plants.

If you have  pots – especially terra cotta pots – in your garden, you probably lose a few every winter.

Is there any thing you can do to protect them? Of course! But first, you need to understand why pots break. As with so many things in a Northwest garden, it’s not the temperature alone that’s the culprit – it’s the moisture.

Pots crack in the winter for one of two reasons:

  1. Terra cotta is highly porous. It absorbs and holds water, sometimes going weeks without drying out. When temperatures drop, this water freezes. As it freezes, it expands. The ice forming inside the clay eventually breaks the pot.
  2. Soil in a poorly drained pot becomes sodden. As the temperature falls, the water in the soil freezes. This causes the volume of material (soil, roots, and ice) to expand. Under pressure, the pot cracks.


What can you do to protect your containers (and the sometimes large investment you’ve made in them)?

Unglazed terra cotta pots are most at risk for winter damage. Clay is highly absorbant and very brittle. Traditional clay flower pots are almost guaranteed to chip, crack, and break during a Northwest winter. To protect them, move the pots into an unheated garage or shed, or even under a deck out of the rain.

If the pots held annuals, and you plan to replant with new flowers in the spring, empty all the soil, and disinfect the pots with a mild bleach solution before storing them. Stack the pots upside down in a dry area for the winter.

Terra cotta pots that have been glazed only on the outside are as much at risk as their unglazed cousins. The glazing is mainly decorative. It does not protect the pot from the elements. Water is still trapped by the clay, with the same unfortunate outcome: cracked and chipped pottery after a hard freeze.

Containers that have been glazed inside and out have a better chance of surviving the winter – but the odds are still against it. Moisture can still build up in the soil or even through the bottom of the container (which is rarely glazed).

If you have decorative terra cotta containers and you want to be sure they make it through the winter – don’t leave them unprotected outside.

Concrete, plastic, and fiberglass containers are much sturdier than clay. They don’t attract moisture, and rarely experience frost or cold damage in the Northwest. New styles and colors make some of these pots – especially the fiberglass ones – every bit as attractive as traditional clay pots.

Don’t fight nature. If you want to leave your pots planted year round, avoid terra cotta.

This post was Part 3 of a series.
Part 1: Caring For Your Winter Garden
Part 2: Frozen Ground

Photo by A. Davey Released under Creative Commons License

30 Nov 2009

Frozen Ground


A Frozen Landscape
A Frozen Landscape

It is not necessarily the ice and snow of winter that kills plants.

In fact, snow and ice can act as insulators, protecting plants from wind and sudden temperature drops. More dangerous than the visible signs of winter is something we rarely notice: soggy, poorly drained soil that repeatedly freezes and thaws.

Plants that sit in wet soil can suffer root damage when the ground freezes. Water in the soil turns to ice crystals, injuring and even killing vital root tissue. Hardy plants can recover from dead top growth. Most require nothing more than a hard pruning. But no plant can recover from severe root damage.

How can you prevent the typically soggy Northwest winter from taking a toll on your garden?

It is surprisingly easy. All you need is well drained soil and a layer of mulch.


How do you turn heavy, Seattle clay into well-drained soil?

  1. Aerate the soil every spring and fall
  2. Add plenty of organic matter

Plants grown in soil rich in organic matter will be healthier, require less water, and usually suffer less insect damage. So what is “organic matter“? Any living thing that you add to your garden is organic matter. As it decomposes, it enriches the soil. Compost, mulch, organic fertizers, minerals, grass clippings, shredded leaves, bark… till it in!

Of course, you won’t turn clay into loam in one season, which is why regular aeration is also important. Aerate and lime your turf areas to improve soil structure. A good organic fertilizer applied in the fall will encourage root growth, rather than top growth. Deep, healthy roots will break up heavy soil.

Never walk on your planting beds, unless you are on a path.

Apply at least a one inch layer of mulch to your flower beds in the fall. Be careful not to press the mulch right up to the stems or to let crater-like pockets form around your plants when the mulch mounds up. You don’t want to trap your plants inside a bowl of freezing water!

Taken together, these steps will pull water down deep into the subsoil where it will not freeze.

This also prevents the phenomena known as “heaving.” As ice forms in the top layer of soil, it expands. This pushes the soil up. If there is a lot of ice, the roots of your plants may be pushed towards – or even above – the surface of the soil. Once again, root damage will kill your garden faster than just the cold.

So remember: the key to winter survival for your garden is a thick layer of organic mulch. Garden bark or compost will protect the soil in the winter and can be turned under in the spring, adding vital organic matter to your garden.

This post was Part 2 of a series.
Part 1: Caring For Your Winter Garden
Part 3: Protect Your Pots

Photo by w.marsh Released under Creative Commons License

28 Nov 2009

Caring for Your Winter Garden

Frost covers a Rhododendron
Frost covers a Rhododendron

Winter gardens are common in the Pacific Northwest. Our winters can be so mild that plants seem to grow all year long.

But this is deceptive. Even when we don’t see the heavy and frequent snows of last year, winter poses risks for the garden. In fact, a covering of snow can provide insulation for plants and protect them from freezing.

Frost and sodden ground are the most common plant killers in our region.

The greatest danger to plant survival is a sudden freeze after a warm period. A plant that has not gone dormant has no defenses against winter kill.

We are going to look at ways to protect your outdoor plants and containers from the cold in a series of posts. Today, we’ll talk about frost.


Around Seattle, our first frost usually occurs in early November and our last frost happens in late March. (These dates are only approximate, and there are microclimates all around Puget Sound with different date ranges.) Young, tender plants, growing plants, and new buds are most suceptible to the cold – so you won’t be suprised to learn that the worst frost damage happens to plants in the fall and spring. During the depths of winter, plants are dormant and better able to weather the cold temperatures.

Our almost constant cloud cover throughout the fall and winter helps to moderate temperature swings between day and night and protects our plants. Surprisingly, it is the beautiful clear days, with sunny, blue skies that bring frosty nights.

 There is no way to avoid frost. Even if we could prevent sunny days in winter, we wouldn’t want to! But we can minimize the damage.

  • Frost damages plants by drawing moisture from the leaves to form the ice crystals. Dehydrated plants suffer the most severe injury, so don’t let plants go completely dry during sunny weather.
  • Bare, dry ground loses heat much more quickly than ground covered with mulch. Although our frosts rarely freeze more than the top inch or two of soil, protect your plants’ roots with a good covering of mulch.
  • Do nothing to encourage new growth. Don’t fertilize. Don’t prune plants in the late fall – wait until late spring, when the last killing frost is past.
  • Don’t over-protect your plants. Plants need to be “hardened off” to survive the winter. As temperatures drop and daylength shortens, your plants will slowly go dormant. Don’t interfere with this cycle for cold hardy plants.
  • Container-grown tender perennials can often be over-wintered by placing them in an unheated garage. Remember – you aren’t trying to keep them blooming year round; you just want to protect tender plants from winter kill. Allow them to go dormant, but don’t let the soil dry out completely.

Despite your planning and best efforts, some plants will inevitably suffer frost damage. Sometimes foliage will die back completely. The plant may appear dead, only to push up new growth from the roots in the spring. That is why it is so important to protect the roots from freezing – the topic we will look at next.

This post was Part 1 of a series.
Part 2: Frozen ground
Part 3: Protect Your Pots

Photo by KaCey97007 Released under Creative Commons License

01 Nov 2009

Autumn in the Pacific Northwest

Fall in the Pacific Northwest
Fall in the Pacific Northwest

Now that temperatures are falling and nights are getting longer, your plants – both indoors and out – will require different care than they received in Spring and Summer.

While indoor plants will not go completely dormant, they will need less water and fertilizer. Your technician will test the soil carefully before watering. It is very easy to overwater in the winter. This, especially when combined with fertilizer, will force plants to continue to grow. Unfortunately, in the low light conditions of a Northwest fall and winter, the growth will be weak and spindly, making your plants prey to all sorts of pests and diseases.

Plantscapes’ technicians will groom your plants and water carefully to encourage compact, healthy foliage.

If you have trouble at home, however, with leggy houseplants, aphids, or mealy bugs, try cutting back on the how much and how often you water. Stop fertilizing entirely until spring. If you aren’t sure how wet – or dry – the soil should be, talk to your Plantscapes’ technician on his or her next visit.  They’ll be happy to advise you.

Outdoor plants may go fully dormant. Turf, for instance, stops growing during the winter. This is the season to encourage deep root growth, not top growth.

Of course, our heavy winter rains make regular irrigation unnecessary. The Plantscapes’ irrigation team will visit your property to turn off your irrigation and to winterize your system. 

Some plants may need to be protected from freezing temperatures. While Plantscapes always selects shrubs and foliage suited to the Northwest, all plants are at risk for root damage in the winter. Variations in temperature can cause the ground to freeze and then thaw. This creates a condition known as “heaving.” If the ground thaws after a hard freeze, it expands. Plants’ roots may be forced closer to the surface by the movement of the earth. There, they may be damaged by the next hard frost.

The best way to protect plants’ root is a good layer of mulch.

If you have plantings in areas that are subject to repeated freezing and thawing, talk to your Customer Service representative about Plantscapes’ bark service. An inch of mulch will protect tender roots in the winter and conserve water in the summer.

Photo by ricardo.martins Released under Creative Commons License