Hidden Valley Hibiscus
Growers & Hybridizers of Exotic, Tropical Hibiscus

THE HVH 2012 ONLINE STORE IS OPEN!


Exotic Hibiscus 'Hollywood Starlet'
Hibiscus 'Tutti Frutti' 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!


 

Visit the HVH Online Store

Tropical Hibiscus 'Belle du Jour'
Belle du Jour in a 6" Pot
The HVH 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!

 

 

Hibiscus In Winter

Answers to Commonly Asked Questions

Overwintering hibiscus is a huge topic for so many of us. These are the questions we get asked daily at this time of year, with answers that we hope will help others too.

Should I prune now or wait until spring?


'Crimson Kiss'
Prune in fall only if the plants will be spending the winter in mild conditions that promote at least some growth. Fall pruning usually results in a lot of new growing points that harden up as fall moves into winter. A prolonged or very cold freeze can damage or kill these new growth shoots. But if you know your hibiscus won't be exposed to a prolonged or very cold freeze, then it is safe to prune them in fall. The short new stems won't grow more than about an inch during the winter. Then when spring warmth arrives, they will take off and produce flowers much earlier than if you had waited to prune in the spring.

If I prune in fall, some stems mold and rot starting at the site of the cut. Can I prevent that?

Yes, that does happen sometimes when pruning is done when the weather is cooler and wetter. When pruning in those conditions it is best to seal the cut with a tree wound or graft sealant immediately after making the cut. There are several products available for this purpose. Our favorite Pruning Sealer comes in a spray bottle and doesn't require painting the sealant with a brush. A good sealant prevents fungus spores from landing in the fresh cut and infecting the plant at the cut point.

Should I stop fertilizing in winter


'Mystic Medallion'
No, this is a common myth, but it's not a good idea. Hibiscus are tropical and, if given a warm environment, will grow and bloom year-round. When healthy, they are never truly dormant, and so require a steady stream of nutrients to maintain optimal health. For those who feed every time they water or every other time, cutting back on fertilizer to an appropriate level occurs naturally. This is because instead of watering every day, as is often the case in summer heat, water is only needed once or twice a week, or even less. Less watering means you're applying less fertilizer to the hibiscus. Since hibiscus don't need as much fertilizer as when they are rapidly growing and forming big flowers, this works out well. If you fertilize once a week or on another time-oriented schedule, you should continue to do so, but cut the amount of fertilizer mixed in the water by half. Only hibiscus stored in a cold and dark garage or basement should have almost all fertilizer stopped, but we recommend this way of overwintering only as a last resort. In better conditions a reasonable amount of fertilizer should be given the hibiscus throughout the winter.


'Rise and Shine'
Any hibiscus fertilizer is better than none, but for hibiscus wintered indoors, the higher the level of nutrition the better. A good fertilizer will help mitigate the stress of living indoors, in a lower-light, low-humidity environment. Our HVH Houseplant Formula was designed specifically for hibiscus grown in these stressful indoor conditions, and provides everything your hibiscus could possibly need indoors in one formula. If you use it all winter, every time you water, your hibiscus will have their best chance at staying happy and healthy indoors, and be ready to burst into bloom when they go back outside in the spring. If you have sunny windows indoors, they may even continue to bloom through the winter.

My hibiscus grew so much this summer that they need to be transplanted. Should I transplant now or wait till spring?

Wait until next spring or early summer to transplant hibiscus. The exception to this is if the hibiscus will spend the winter in very warm conditions. For example, one of our fellow hibiscus lovers built a fully enclosed grow room inside his garage, complete with 1000 watt HID lights, and a heating system that keeps the room above 70°F (21°C) all winter. In conditions like this, hibiscus can continue to grow vigorously and transplanting them is no problem in fall or winter.

When should I move my hibiscus inside for winter - at the last minute before cold sets in or earlier?


'Chariots of Fire'
Over the years, we have had better luck moving them inside before they are stressed by the increasing cold. Oftentimes people leave the plants outside until too late - until the first frosty night alerts them that it's time to move them in. The problem with this is that the hibiscus make the stressful move into the house just after being weakened by the outside cold. In our experience, it's better if they are moved when still strong and healthy. Another factor is that tip die-back disease increases once the weather cools down in fall, but does not happen nearly as often once the plants are moved inside.

I have fairly good windows inside for my hibiscus, but no direct sun in winter. Is this good enough?

Remember, the most important need for hibiscus in winter is warmth. The more the better. They also need some light so, if the windows are not able to provide enough, placing any type of lamp near the hibiscus will help them get sufficient light to stay healthy. Light is a cumulative thing for plants - what matters is the total amount of light they receive from all sources throughout the day and night. If a light can be left on all night that is a big help, or if one can be placed on a timer so that it shines 18 hours a day near the hibiscus that will make a difference, too. Growth and blooms are not that important in winter - what we are after is maintaining a healthy green plant until next spring and for that the hibiscus need mainly warmth with at least some light.

My hibiscus are planted in the ground and can't be moved during winter. What can I do to protect them?


'Gabriel'
In climates like southern California where temperatures rarely go below 30°F (-1°C), some people have reported success using frost cloth to cover their hibiscus at night. Also called row covers, this lightweight woven material is able to trap heat inside while still allowing water and light to penetrate. The heavier versions of it are best and claim to provide up to 10 degrees of protection if used properly. If you try these, be sure to get enough to cover the hibiscus and to hang all the way down to the ground because they work by trapping heat that comes out of the ground at night. It is also possible to place lights, such as outdoor Christmas lights, under the frost cloth and the heat that these give off adds an extra amount of protection. On very cold nights, dripping water into the root-zone throughout the night can help even more, because flowing water is always warmer than freezing and will keep the roots of the hibiscus from freezing.

 


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:

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.