High molar mass polyethylenes with bromine atoms placed on each and every 21st, 19th, 15th, or 9th backbone carbon crystallize into two distinctive layered polymorphs by changing undercooling. Crystallization at low temperatures produces Form I, a planar all-trans conformation, while at higher temperatures gauche conformers set for backbone bonds adjacent to the methine due to a close intermolecular staggering of bromines resulting in a herringbone Form II structure. In this work, the sharp range of isothermal crystallization temperatures for the transition between Form I and Form II is first identified via WARD and melting behaviors for all members of the series. Furthermore, the temperature dependence of the isothermal linear spherulitic growth rates of Form II has been studied for a wide range of crystallization temperatures. The linear growth rates display a discrete minimum with decreasing temperature at a crystallization temperature near the melting point of Form I, a feature which is reminiscent of the minimum found in the crystallization rate of long-chain n-alkanes. Changes in spherulitic morphology and the growth rate minima are analyzed on the basis of self-poisoning at the growth front resulting from frequent but unstable Form I depositions on the growth surface of Form II. The similarity with the behavior observed in the growth of long-chain n-alkanes crystallites supports a polymer crystallization process controlled by events that take place at the crystal growth front.