Ask Mr. Smarty Plants

Since the Magnolia grandiflora 'Little Gem" is a cultivar of Magnolia grandiflora (Southern magnolia), it will not appear in our Native Plant Database. However, we feel it is closely enough related that we can use data on the native magnolia to try and figure out what is going on. First, this USDA Plant Profiles county map of Texas, with the green counties being the one where the Southern Magnolia grows,  you will see that the closest county to Collins and Denton Counties where that tree grows naturally is Van Zandt County, with the other counties being farther south and east.

If you follow the plant link above, you will learn that the first choice for this tree is a rich, porous, acid soil. Under Condition Comments:

"Conditions Comments: Southern magnolia is a relatively fast-growing tree. It casts a dark shade, making underplanting difficult. Prune after blooming during the growing season because dormant magnolias do not easily heal. Fallen leaves are messy and never seem to decompose. They can be chopped with a rotary mower and blown back under the branches to recycle nutients. Must be given protection from winter winds and sun in northern part of its range. Relatively pest free."

Please see this list of plants native to the Blackland Prairies of Texas, and read the description of the soils; the plant list for that area does not include Magnolia grandiflora (Southern magnolia). We suspect that the soil not being what the magnolia does best in and possibly the way the soil was prepared when the trees were planted has something to do with the problem. Also, even three years after being planted, the chance of transplant shock is still there. We always recommend that woody plants, trees and shrubs, be planted in Texas in late Fall or Winter, while the plants are dormant and will be less likely to suffer damage. We also recommend that you amend the soil when digging the tree to provide better drainage.

From the Blackland Prairies list cited above, we found this comment: "The upland blacklands are dark, calcareous shrink-swell clayey soils, changing gradually with depth to light marls or chalks." Again, pure conjecture, we are wondering if either some damage was done to the roots of the tree when it was planted, or rainwater could not drain away sufficiently in the clay soils to protect the roots from rot. In answer to your question about fertilizer: no. The purpose of fertilizers is to encourage the plant to grow new leaves. That stresses the tree; a tree already under stress does not need that.

Many of the same answers pertain to Ilex vomitoria (Yaupon). You will see from this USDA Plant Profile map that it is native to Denton Co. From our webpage on that plant:  "Moist or well drained, sandy, loamy, clay, limestone, or gravelly soils.  Yaupon is a versatile plant that tolerates drought and poor drainage." This plant does appear on the list of Blackland Prairie plants.

We can only conclude, in both cases, that the decline of the plants does not have to do with anything that is happening now, but something that happened (or didn't happen) when the plants were being put in the ground. It is difficult to put compost or some other amendment to good drainage in a hole dug three years ago. The fact that the 'Little Gem" is a cultivar also complicates the situation as there could be factors we don't know about involving the cultivar.

Our suggestion, in both plants, is to give both plants a chance to recover. Unless it gets very dry again, don't water either tree. You could try mulching the roots of all the woody plants with a good quality organic mulch. This will help keep down weeds, hold moisture, protect the plant roots and looks and smells good. Particularly, the yaupon is a tough plant, native to your area, and more likely to recover. We suggest that any time you plant garden selections you research first, on our Native Plant Database, whether the plant is native and get good planting instructions, particularly in reference to drainage.