Ask Mr. Smarty Plants

There are 3 magnolias native to Texas: Magnolia grandiflora (Southern magnolia), Magnolia pyramidata (Pyramid magnolia), and Magnolia virginiana (Sweetbay). Parker County is in the Blackland Prairie of Texas, and you can read the list of plants recommended for that area, although the list contains no magnolias. Here is a description of the soils in that area:

"The Blackland Prairies area intermingles with the Post Oak Savannah in the southeast and has divisions known as the San Antonio and Fayette Prairies. This rolling and well-dissected prairie represents the southern extension of the true prairie that occurs from Texas to Canada. The upland blacklands are dark, calcareous shrink-swell clayey soils, changing gradually with depth to light marls or chalks. Bottomland soils are generally reddish brown to dark gray, slightly acid to calcareous, loamy to clayey and alluvial. The soils are inherently productive and fertile, but many have lost productivity through erosion and continuous cropping."

The soil description for Magnolia grandiflora (Southern magnolia) is:

"Soil Description: Rich, porous, acid soils. Sandy, Sandy Loam, Medium Loam, Clay Loam Clay, Acid-based, Calcareous"

According to this Plant Profile Map for that tree, it grows mostly in East Texas, where the soils are more acidic, but Parker County is not far from that area, so it's worth a try.

From our webpage on Magnolia grandiflora (Southern magnolia), we suggest you read the whole page), here are the Propagation Instructions:

"Propagation

Propagation Material: Seeds
Description: Propagation methods include the use of fresh seed sown in fall, stratified seed, or wounded, semi-hardwood cuttings taken in summer. The seed of evergreen magnolias seems to germinate more quickly than that of the deciduous varieties.
Seed Collection: Gather as soon as comes drop or the red seeds appear. When ripe, the seeds are bright red, fleshy, oily, soft on the outside and stony on the inside. Clean and store in moist sand or sphagnum moss in refrigerator. Cold, moist storage also serves at stratification.
Seed Treatment: Stored seed must be kept moist and cool which will also serve as stratification. Stratify at least 60 days.
Commercially Avail: yes
Maintenance: Maintain moist soil, Remove dead growth, Prevent complete soil dryness, Do not prune lower limbs & leaves, Fertilize in spring, mid-season & fall with azalea/camellia-type fertilizer"

"Growing Conditions

Water Use: High
Light Requirement: Part Shade
Soil Moisture: Dry
CaCO3 Tolerance: Low
Cold Tolerant: yes
Soil Description: Rich, porous, acid soils. Sandy, Sandy Loam, Medium Loam, Clay Loam Clay, Acid-based, Calcareous
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. Seedlings are quite sensitive to frost."