Gardening Q&A

As a California Bountiful reader, you have the opportunity to get your seasonal gardening questions answered by gardening expert Pat Rubin. What do you want to know, now that winter is showing signs of making its exit?

Editor's note: Jean wrote to us earlier about problems with her citrus trees.

Thank you for the follow-up. The orange tree that is in the ground is a fairly young tree. We planted it a year ago. Although it did drop most of its leaves, it is now growing lots of new ones. The other tree is a lemon tree and in a large plastic pot. It has lots of fruit on it, but the tips of the leaves are yellow. I noticed that it does have "something" eating it on the underside of the leaf. I am thinking of how to replant this tree in the ground. It looks like that would be a big undertaking.

I do appreciate all your advice. I was very surprised at how quickly I received an email from you and all the follow-up. Thank you so much!

Jean

Dear Jean,
It sounds like the citrus tree in the pot needs repotting or transplanting into the ground. Plus I'd recommend a fertilizer for citrus—just check at the local nursery and follow the directions. However, that said, if it is producing fruit, it can't be too terribly stressed. If you decide to replant, pick any ripe or near-ripe fruit first.

If you repot into a larger pot, choose a planting mix that has multiple ingredients rather than a sterile potting mix. Loosen the roots of the tree when you take them out of the old pot.

For planting in the ground, dig the hole first (it should be slightly wider and deeper than the root ball), loosen the roots as above, add compost and plant. Make sure the soil is at the same level against the trunk of the plant as it was in the pot. The soil level could be ever so slightly lower since the soil will settle once it is watered.

As far as something chewing on the leaves, I think it would be best to either contact your local Master Gardeners office (look for the Farm Advisor's Office under your county listings) or take a sample of the leaves into the nursery and have someone take a look.

Best of luck!
Pat

This May will be the third year for our grapevines (in El Dorado Hills). No worthwhile production so far. This year's green leaves starting; full sun, drip irrigation. What basic care could you recommend for this low-information gardener? Thank you very much.

Ann G.

Dear Ann,

Thanks for the question. Luckily, you are in a great area for growing grapes in the backyard.

It does take a few years for the plants to make any significant amounts of fruit. That said, I'm hoping your plants are getting plenty of sun and that you know how to prune them each year.

The Sacramento County Master Gardeners have an amazing demonstration garden of fruit trees, grapevines, berries, vegetables and more at the Fair Oaks Horticulture Center, and it isn't far from El Dorado Hills. They do lots of demonstrations and workshops for people.

Here is a link to their website. Click on "grapes" from the menu on the left side of the page. ucanr.edu/sites/sacmg/Fair_Oaks_Horticulture_Center

Let me know if this helps.

On one of my citrus trees, the leaves are turning yellow on the ends. The other tree has leaves that are falling off. What can I do?

Jean

Dear Jean,

I'm not sure whether the plants are in containers or in the ground, so I will answer for both.

First off, some leaves on the citrus tree—mainly the older ones—will turn yellow during late winter and even drop off. The problem should disappear by April or May. This is normal.

If the plant is in the original container from the nursery, the plant is likely root-bound and needs to be repotted. It is also possible that the tree has outgrown the pot and needs a bigger one with fresh soil. The new container should be at least twice as deep and wide as the original so the roots can spread out. Use a good planting mix with plenty of compost.

If the tree is already in a suitable container, it could be lacking nitrogen and iron. There are plenty of fertilizer mixes made especially for citrus. I like to give the plant a more diluted application of fertilizer than the label says, but do it slightly more often than the label says. That is solely my preference, and certainly following the label exactly is what the manufacturer would recommend.

I'd also suggest adding a thin layer of compost to the top of the soil, but not so much that it affects the height of the soil against the tree trunk. Keep it away from direct contact with the trunk. As you water the plant, the nutrients in the compost will be taken down into the soil.

If the plant is in the ground, give it a light application of compost several times during the growing season and also use a light application of fertilizer.

You could also be overwatering. Check the soil before watering to make sure it isn't already wet.

I hope this helps. If you have any more questions, please write again.

Some critter is coming into my garden at night and digging round divots in the mulch and then getting in the raised beds and digging around the vegetable plants. It doesn't seem to eat the plants, but they keep getting dug up. I'm starting to dread going out to the garden in the morning. What's happening?

I know the answer to this one because I've had the same problem. You've got skunks coming into the garden at night looking for grubs and earthworms in your nice, moist, friable soil. It's a regular feast for them. You could trap the skunks and call your local animal control to find out what to do about them, or you can prevent them from coming into the garden in the first place.

The only way to do that is with a barrier. Skunks have bad eyesight and are poor climbers, so the barrier doesn't have to be high. One year we used shade cloth lashed to conduit to keep them out of the raised bed garden. We finally fenced the entire garden with a picket fence, making sure to put the pickets closely together so the skunks couldn't slip through. I would also suggest watering early in the morning so the ground around the garden is dry by nighttime, and the area won't be so attractive to them.

I've planted green bean seeds twice, and nothing comes up. Other seeds have come up, so what's wrong with the beans?

I'd guess the soil is still too cold for them, so they rot rather than germinate. Bean seeds are especially susceptible to cold soil, so try again at the end of April. "Farmer Fred" Hoffman, master gardener and Northern California radio host, always says the best way to determine whether the soil is warm enough for planting is to sit on it.

I have slugs and aphids. Need I say more?

Yikes! For the slugs, you can go out at night and handpick them. There are slug baits available that are nontoxic to pets and children, and they work really well. For the aphids, the easiest thing to do is hose them off with a forceful spray of water. A few days of this seems to discourage them. Also look for ants, since they may be bringing the aphids to the plants. If so, you need to get rid of the ants. There are sticky products designed to thwart them. Check your local nursery.

See how Pat answered your questions earlier this year.

• January/February 2013

About Pat Rubin, California Bountiful's gardening expert

Pat Rubin

For Pat Rubin, gardening is more than just dirt and plants. "It's about history, romance, adventure and people," she says. "And it should be fun."

California Bountiful's gardening columnist has lived and chronicled this fun, hands-in-the-dirt approach for years—and for additional publications including Fine Gardening, Pacific Horticulture, Christian Science Monitor, Family Circle and The Sacramento Bee. Pat has also volunteered as a Master Gardener, speaks to garden clubs and appears regularly on gardening radio shows.

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