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Hibiscus 'Chariots of Fire' 'P's Purple' in Page Border

Welcome to Hidden Valley Hibiscus! We hope you like our exotic, tropical hibiscus! We grow over 300 hibiscus hybrids, or varieties - "cultivars" in hibiscus lingo. Most of our varieties are hybridized right here in our own greenhouses, and are unique to HVH. All these new hybrid hibiscus are descendants of the small hibiscus flowers we all know well, but the new "exotic" or "fancy" hibiscus hybrids are huge, multi-colored, multi-shaped, splashy, and amazing. Browse our website and our Online Store to see what we mean. We ship our potted hibiscus all over the United States and to many other countries too. Plants arrive ready to unwrap and sit in a window, on a patio, or out in a garden. Plants in the 6" pot size or larger arrive budded up and ready to bloom. The Hibiscus Care section of our website has all the information you need to successfully grow these beautiful flowers. Enjoy!

Belle du Jour in a 6" Pot

The HVH 2010 Online Store is open with many exotic, tropical hibiscus varieties and all the care products your hibiscus need to stay happy and healthy. Happy shopping!

"Just HAD to let you know - the plants arrived today... someone had to wake me up, because I SWOONED... they are so beautiful! Thank you so much for your care, the awesome blooming hibiscus and the amazing customer service on my request and in RECORD time. Please know that I am now a customer and fan forever. Thank you" Diane D

"Thank you so much. I received the plants last week and they are gorgeous. I just placed an order for two more plants. Again, thank you for the beauties." Sheila J

Diane and Sheila are just a few of the many happy HVH customers. Read more customer comments here! The photo above shows the typical size of plants in 6" pots (this is cultivar 'Belle du Jour') at the time of shipping, although size varies by cultivar and we don't guarantee the open blooms. See Terms & Conditions for more information on our guarantees and shipping policy.

Expert Advice
by Charles & Cindy Black

Charles & Cindy Black answer hibiscus questions. Charles & Cindy are world renowned hybridizers and growers of exotic hibiscus, as well as the owners of Hidden Valley Hibiscus. They have created many award-winning hibiscus varieties, such as Heaven Scent, Lady in Waiting, Her Majesty, Simple Pleasures, and Love Story. In this column, they share their expertise in growing hibiscus with our visitors. Enjoy!

Beat the Heat

Growing Hibiscus When it's Hot, Hot, Hot!

'Wild Child'

What a summer many of us have had! From record temps and wildfires around Moscow, to triple digit readings in the northeast USA, it has been a very hot summer for many. News reports are saying that 2010 has been the warmest year on record worldwide. On the other hand, here in southern California we are still shivering and waiting for summer to come (though sympathizing with our overheated brethren) since we have had a record cool summer here for some reason. But the heat will surely come to us as well during the next 3 months, so we need to be prepared.

As we have said many times, hibiscus like conditions that are very similar to what people like - not too hot and not too cold. Sunny but not too sunny, and so forth. Very hot summers stress both the hibiscus and the people who tend to them. So what can we do to make the best of hot weather? There's nothing we can do to change the daily temperatures, but we can offer some relief to our hibiscus. Doing so can make all the difference in whether they continue to bloom. Here are some tips that may help:

Give Your Hibiscus Some Shade:

Move potted plants to areas that are shaded all or part of the day. We've seen hibiscus perform great in locations where they get some morning direct sun followed by shade the rest of the day. Our big porch is like that and we get blooms out there all summer. Trees can offer some shade, fences, walls, side of houses - all can provide shade during part of the day, and this will help hibiscus a lot.

'Phantom'

Remember, all conditions are interrelated with hibiscus. They can take more sun if temperatures are lower, just as they can take higher temperatures if there is less sun. This tells us that shade during the hottest part of the day gives the hibiscus the most benefit. In situations where this is not feasible, it is still worthwhile providing for shade during the early part of day.

Almost all commercial hibiscus growers come to the conclusion that growing their plants under shade cloth or shade painted greenhouse plastic results in the best looking plants. Leaves become larger and darker green, and fewer buds fall off before opening due to excess heat. You too can rig up some shade cloth over your patio or deck or parts of your garden. Both you and your hibiscus will enjoy the dappled light created by shade cloth. Usually 50% shade cloth is used, but any rating from 70%-30% will help and provide some relief. If you are not up to building a structure to attach the cloth to, there are also available easy-to-assemble canopies with metal poles that come fitted with shade cloth.

Cool Them Down

'Goodbye Girl'

One trick we use in the greenhouse on particularly hot summer days is to spray the plants and the floor around them with water during the afternoon heat. The water quickly evaporates and provides both cooling and humidity. This is not watering the plants, it is cooling them off and providing them relative humidity that they like. It can be done several times during a really hot day and the results are noticeable.

A more high tech way of achieving the same thing is to install a mist system above the hibiscus. A true mist system will both cool the plants and provide humidity without wetting the leaves and can be left on all afternoon. A coarser mist system will achieve similar results to a hose spraying and will wet the leaves. That type of system should be connected to a timer that turns the mist on and off several times during the day.

Water Them Well and Often

Plants transpire just like people perspire. To do that they need to have plenty of water available to the roots. It is a little known fact that potted plants can use up most of the water added to the pot in the morning by late afternoon. Experiments have shown that it is actually better to divide the water into two parts and give one part in the morning and the second part in mid-afternoon. The same total amount of water is received by the plants but they grow bigger and faster if it is divided into two doses. When watering only once in the morning on very hot days the hibiscus can reach the pre-wilt stage by late afternoon. You can't see any wilt yet but the hibiscus are stressed and can be set back if this happens often. One of the first consequences of this type of stress is fewer buds and flowers.

'Sparkling Water'

Watering takes time. If you do it by hand you need to take the time to make sure that the water soaks all the way through the pot. It is easier to do this with a watering can than a hose but the hose is faster and many people use hoses. The easiest way to thoroughly water all the pots is to fill each pot to the rim with water and then move to the next pot. This is usually not enough water so the trick is to water all nearby pots and then water them all a second time before moving on to the next group of pots.

To be on the safe side, tip one or two root balls out of their pots to see if your technique is actually watering the entire rootball. People are often shocked to find that the water only penetrated a few inches down into the rootball. You can see the dark area that is wet and the lower dry area of the rootball that is still dry.If you see this, it means you need to spend more time watering each pot or return to each pot for a second or third time so that when you are done each pot is soaked all the way through to the bottom.

Hibiscus planted in the ground do best with deep watering. If you water with a hose plan on spending plenty of time watering so that a deep soaking is achieved. Far better is a drip system or sprinklers on a timer that can be set for a sufficient period to soak well down into and a little past the root zone. Again, the only way to know for sure is to get the shovel or trowel out and dig down into the earth after watering. You don't need to do this often once you learn how deep the water is penetrating.

Pot Them With Summer Conditions In Mind

'Wine Spritzer'

Pots are important. They should be big enough to provide plenty of water but not so big that they never dry out. It is often quite amazing to see how hibiscus take off when given more room for the roots to grow. Eventually every hibiscus in a pot will want to be moved to a larger pot. If that does not happen they start to languish and eventually decline.

As an alternative to moving a hibiscus to a larger pot, you can do root pruning on them. Though this sounds drastic, in reality it works out quite well usually. During spring or early summer, prune the roots by removing 1/3 of the rootball from the bottom and sides. Then, using good quality potting mix, repot the hibiscus in the same pot or same size pot that it was removed from. This allows fresh root growth without a larger pot. This process will refresh the entire plant, and good top growth will follow new root growth.

Exposing plant pots to direct sunlight can cause overheating of the root ball. One technique for preventing this is to place the plastic pot inside a larger ceramic pot. This looks nice and protects the roots from becoming too hot. One hibiscus lover we know, who has a lot of big plastic pots, paints one side of each pot with reflective white paint. He orients the pots so that the hot afternoon sun strikes the white paint and is reflected away instead of being absorbed by the pot.

'High Voltage'

Pots come in different materials. When choosing one for hibiscus consider the way it will either insulate the roots from the heat of the sun or possibly make the situation worse by absorbing all the heat. Heavy clay pots look nice and provide some sun protection to the roots but the drawback is that they are porous and water escapes from the sides of the pot. Sometimes they are offered with a sealant already applied to the inside of the pot which will help with water loss. Plastic retains moisture much better, but also absorbs too much heat. Putting moisture-retaining plastic pots inside cooling ceramic pots can solve both problems.

Self watering pots are available from many stores - even some of the big box stores carry them. This type of pot contains a water reservoir that is refilled when it dries out. The water is wicked to the potting soil as the soil dries and in theory keeps the potting soil evenly moist at all times. In practice, most of these pots work quite well for hibiscus and they grow great in them. We found that allowing the reservoir to completely dry out before refilling is helpful in preventing some of the problems that can come from constantly wet soil. Drawbacks are the high cost of theses pots and the fact that you need to remember to refill the pots every week or so. Daily watering by hand is easy to remember, but watering once every few days tends to be harder to keep track of.

Science Offers Some Help

The traditional techniques suggested above are tried, true, and known to work very well. But modern science also offers a few tricks to help beat the heat.

• Anti-Transpirants:

  These are products that can be sprayed on the plant leaves that coat them and help conserve moisture inside the plant. These are also used to protect the plants from cold during winter. In our experience they do help some, but not a whole lot. Other heat-beating measures need to be used along with anti-transpirants if you decide to try them.

'All That Jazz'

• Moisture-Retaining Substances:

  These are added to the potting mix where they absorb more moisture than potting mix can absorb. When the potting mix dries out they give back the stored water to the potting mix. This lets each watering last longer and is an alternative to watering more than once a day in summer conditions. We have not tried these, but they do seem promising. When they first came out there were problems of various sorts, but the newer moisture-retaining products are now considered to be much more reliable. Please let us know your results if you try them.

We hope you have a great summer and that you and your hibiscus flourish despite the high temperatures that seem to dominate this year! If you have any tips or tricks to contribute, please share them with us in the Extreme Heat Thread of our HVH Forum.

Magnesium

An Essential Nutrient for Healthy Hibiscus

Potassium is the essential mineral for blooming in hibiscus, but another mineral, magnesium, is essential for glossy, green leaves and good growth. Interestingly enough, these two minerals actually compete in nature. The more potassium a plant needs, the more magnesium it also needs, and too much of one without balancing amounts of the other can create a deficiency. Potassium deficiency shows up in a lack of blooms, poor flower color, and weak, spindly wood. Magnesium deficiency shows up in yellow leaves, or chlorosis. But constantly giving our hibiscus potassium to keep them blooming with big colorful flowers, we can actually create a magnesium deficiency that stresses the whole plant. At the risk of sounding like science geeks, let's see if we can explain this . . .

Why Do Plants Need Magnesium?

Magnesium (Mg) is at the Center of Every Molecule of Chlorophyll

Magnesium is one of the most essential minerals for all green parts of a plant because it is used to make chlorophyll, the green pigment in plants that turns water, air, and sunlight into food for the plant. Magnesium is the central atom that the chlorophyll molecule is made around. Without magnesium, plants just can't make chlorophyll, and without chlorophyll, plants slowly die. Look at the diagram of a chlorophyll molecule at right. It may look like confusing gibberish to you, but right in the middle you see a magnesium atom (Mg) surrounded by four nitrogen atoms (N). Everything else is just oxygen, hydrogen, and carbon, the basic atoms in air and water. Even if you understand nothing else, it's easy to see that to make chlorophyll, plants must have enough magnesium, as well as the nitrogen we give them constantly in our fertilizers.

How Do Hibiscus Become Deficient in Magnesium

Good fertilizers should contain magnesium in the right ratio for the plants they are designed for. Our HVH Special Blend Fertilizer contains the ratio of magnesium, nitrogen, potassium, phosphorus and other micronutrients that hibiscus need. If you use a good hibiscus fertilizer alone, your hibiscus should be fine. Our hibiscus get into trouble when we increase potassium by adding nutrients like the HVH Hibiscus Booster to our plants to make them bloom more abundantly and with brighter colors. With all this extra potassium added to our plants, they need an increase in magnesium to keep them green and growing. All the blooming can stress the plant if we don't provide the magnesium the plant needs to also grow green leaves.

Other conditions that can cause magnesium deficiency are poor soil, very hard or alkaline water or soil, not using enough fertilizer or not using a high quality fertilizer. High heat in late summer can exacerbate magnesium deficiency, so if you haven't seen signs of it before, you may see it at this time of year.

What are the Symptoms of Magnesium Deficiency?

Symptom of Magnesium Deficiency Young upper leaves are green and healthy. Older lower leaves are yellow with dark green veins.

Magnesium deficiency shows up in yellow leaves, or chlorosis, like so many other hibiscus ailments! But with magnesium deficiency, the oldest leaves turn yellow between the veins. Look down low on your plants for leaves that have dark green veins with yellow or yellow and brown between the veins, sometimes with brown edges. The plant tries to send all the magnesium it has up to the tips to the new growth, so the chlorophyll in the lower leaves is broken down and disappears, leaving the strange green-veined yellow look that is the tell-tale sign of magnesium deficiency.

Using Epsom Salts to Supplement Magnesium

For many gardeners, magnesium deficiency can be cured quickly, inexpensively, and easily with epsom salts from the grocery store or drug store. We have bought "horticultural grade" epsom salts and compared them to grocery store epsom salts, and can find no difference in the results. Epsom salts are very water-soluble and can be sprayed onto plant leaves or drenched into pots to supply the extra magnesium that your hibiscus need from time to time. Fastest results are obtained by using Magnesium as a foliar spray. Longest lasting results are obtained by mixing it into the soil.

TO USE IN THE SOIL:

• First water with plain water to moisten soil.
• Sprinkle magnesium on top of the soil under the plant
• Water lightly to wet magnesium
• Use 1 teaspoon of magnesium for a plant in a 4" pot.
• Use 2 teaspoons of magnesium for a plant in a 6" pot.
• Use 1 Tablespoons of magnesium for a plant in an 8" pot.
• Use 2 Tablespoons of magnesium for a plant in a 2-gallon pot.
• Use 1/4 cup of magnesium for large plants in the ground.

Epsom salts work well for hibiscus planted in the ground in areas with neutral or acidic soil, or for plant in pots where the water drains out the bottom and isn't constantly taken back up into the pot.

Hibiscus that Need Chelated Magnesium

Hibiscus grown indoors with trays under the pots, or in higher-stress lower-light conditions do better with a rapidly absorbable chelated form of magnesium. Likewise, hibiscus grown in areas with hard or alkaline water or alkaline soil will often not be able to absorb the magnesium in epsom salts before it runs out of the soil. This has been our problem with epsom salts here in Southern California where the water is very hard. The minerals in the hard water and alkaline soil compete with the epsom salts, and block the uptake of magnesium from all sources. The molecules in chelated magnesium are able to enter the plant much more easily and are absorbed very quickly into all parts of the plant, so we find it works much better in our hard-water Southern California conditions.

This is our favorite chelated magnesium product, one that we have used for years ourselves and at long last have available for our customers: Fulmag Chelated Magnesium. This magnesium is highly absorbable, instantly usable for all parts of the hibiscus plant, and gentle enough for frequent use. It contains no nitrogen or other salts that can burn your plants, and it is completely compatible with all our other products. It can be mixed right into the fertilizer of booster water with your regular nutritional program.

NOTE: If you use the HVH Houseplant Formula as the main fertilizer for your hibiscus, you do not need to use extra magnesium. The HVH Houseplant Formula contains high doses of magnesium in order to provide the extra nutrition that plants in less-than-optimal growing conditions need.